Lua if statement not equal. Switching between two strings like booleans.

Lua if statement not equal. To learn more, see our tips on writing great answers.
 


Lua if statement not equal Discussion on whether to use 'if not' or '~=' in Roblox scripting. That's why Lua evaluatesnot "a" == "b" as (not "a") == "b" which resolves to false == "b" and finally to false. local E = {} local my_val = ((frameActions or E). The variable is npcSpecimen. 1 syntax with more features; Luau does support string literal extensions but does not support other 5. If statements will allow you to specify what code to run when a condition is true, and when it isn’t. We call it the nested if conditions. user14189755 user14189755. While still largely relevant for later versions, there are 4. In the else case, a recursive call may return something, but then you ignore that returned value. When you have tables and you want sets, because it's not a string for example, then add a checksum or tostring on it for Making statements based on opinion; back them up with references or personal Your function isn't checking the aura that caused the event. if weather == "bad" then. Sign The Logical Operators section of Programming in Lua explains the idiom: Another useful idiom is (a and b) or c (or simply a and b or c, because and has a higher precedence than or), which is equivalent to the C expression. But you are comparing them with: t = true f = nil which is incorrect, because though both false and nil are false values, they are not the same, i. find() string. Variables So the statement 2 + 2 == 4 can be read as "two plus two is equal to four". Can anyone help? Here are two variations that I've tried, both ended up with the same output. In this example, we're creating two variables a and b and using logical operator we've performed a logical AND operation and printed the result −. Any variable in a table (including _G, the table where globals reside) without a value gives a value of nil when indexed. 3. Dashboard Learn Store Talent Forum Roadmap. (A == B) is not true. 3. To learn more, see our tips on writing great answers. Parent if TextLabel. This is, because you can compare numbers with == just like you can compare boolean values with ==. How to check if a value is equal or not equal to one of multiple values in Lua? 4. Combining Statements local isAlive = false local age = 19 if isAlive and age > 18 then print ( "good" ) elseif not isAlive or age < 18 then print ( "either dead or under 18" ) end Next: While/For I am newly learning lua, and wrote a small starter script that takes user input and should be comparing it to assigned values and offering a response based on the if/then statement. If the condition is false, the code block inside the if statement does not run. contentEquals(str2) With the first one (actually also equalsIgnoreCase()) you will compare two instances of String while with the second one you can compare a String with any instance of implementation of CharSequence. You're right. 2. ) Note that future versions of Lua extend the Lua 5. str2) else print(str1 . – jv110. If The equal sign is causing the error, and it's not required. In this example, we're showing the usage of if else statement. otherwise you'll just need to use an if-then-else statement. This article examines Lua if statements, Conditionals in Lua allow your script to make decisions based on whether certain conditions are true or false. 1); this means when you combine some of the mathematical operators with them they will change from a string datatype to a number datatype. For complex logic, you can using if-else condition inside another if condition. Elseif Statements. Most notably, PICO-8 does not include the Lua standard library, and Maybe. The (easiest) way around this is something called elseif. The first is equality between elements of the domain =. When you build and execute the above program, it produces the following result − You can use the keyword not to get the opposite of the truth value. There Use the logical operators 'and', 'or', and 'not' to create more complex conditions when necessary. You can use a variable, and assume it's true. Like control structures, all logical operators consider both false and nil as false, and anything else as true. I want to write an if/else statement that tests if the value of a text input does NOT equal either one of two different values. No, it's not like Perl, where the condition of `if' and similar statements can follow the statement. if not keySet[key2] then return false end end -- comparison finished - objects are equal do not compare again oComparisons[o2] = true return true end function pequals(o1, o2, ignore Making statements based on opinion; back them up with references or Think of it this way: You have to check each element in the first array to its counterpart in the second. Sign Beware that, unlike some other scripting languages, Lua considers both zero and the empty string as true in conditional tests. Stack Overflow. Sign up using Google Lua string. The else-part is optional. Sign I'm trying to figure out an easier way to determine if a variable is one of several values in Lua. Lua - Operators - An operator is a symbol that tells the interpreter to perform specific mathematical or logical manipulations. ; Leveraging Lua's Features If the values have different types, Lua considers them different values. To learn more, see our tips on If you want to check wether two values are equal you need to use the equality operator ==, not the assignment operator =. Sign up or log in. ” It From the code, I'm guessing brown and black are boolean types, which are either true or false. local function inString(s, substring) return s:find(substring, 1, true) end list Hmm. if A and B and C [or if] A and D [or if] A and E then X End. However, that's a little redundant, you don't need t and f in the if-statements. Add a comment | Your Answer Reminder: Answers generated by artificial intelligence tools are not allowed on Stack Overflow. Commented May 3, 2020 at 17:41. Learn more. If you want to check wether two values are unequal use the unequal But if you need to know whether Lua considers it an actual number or not, rather than a string, use 'number' == type(foo) in your test conditions. 1 – if then else. This first edition was written for Lua 5. The words if, then and end are keywords. For instance, we can select the maximum of two numbers x and y with a statement like If a equals b, Lua will not check if a equals c. Otherwise returns 0. So you can't "check if UnitAura is not "Heating Up"", because you simply don't know what aura caused the event. So f(1) is 0, and f(x) is 1 for every x that does not equal 1. For instance, after the code Example 2 – Utilize the NOT Function with a Not Equal to Statement in Excel. For example: local x = 10 if x > 5 then print("x is greater than 5") end In this case, since `x` is indeed greater than `5`, the output will be `x is greater than 5`. In the case of the code below, no matter which number the user inputs, the only code that runs is the code under the if statement. – Well I am learning Lua at the moment and I wanted to write a little script. Generally, Lua script based on some types of operators which used upon the script and it requires the project and application for both authenticating and non-authenticating purpose. Creator Hub. This will always be the same as bool or true which will always be true. What do I want to achieve? and/or statement? What is the issue? I don’t know to do an and/or statement in Lua. In the original version of Lua, that was never originally seen outside Tecgraf, the first not-equal operator was actually literally NE. Because it is a subset, not all features of Lua are supported. Lua supports an almost conventional set of statements, similar to those in Pascal or C. Flow Diagram Example. Explanation: This is how lua will evaluate second line (consider that frameActions = {foo='bar'}): I have written a program to print a matrix after some computations and I am getting an output of nan for all elements. In math, writing ~= means “Approximately equal to. Assuming the file is t. The following table summarizes how logical Lua is a programming language designed primarily for embedded systems. As we’ve seen, Lua is made up of chunks and statements. In the following Lua code: function eq_event(op1, op2) if op1 == op2 then return true end local h = getequalhandler(op1, op2) if h then Making statements based on opinion; back them up with references or personal experience. I have a variable inside the second if layer that I want to use in the first layer. Strings that quack like numbers Lua has a controversial "feature" where it coerces strings to numbers if you do arithmetic on them, and coerces numbers to strings if you do arithmetic on them; print just calls tostring internally, which doesn't quote strings, so strings very much "quack like numbers". I was wondering if there was a way in lua to ask if a value equals multiple diferant separate values For example: if x. -- _,v stands for variables that we are going to read from inventory table -- we can't do it directly, however; **ipairs** function will prepare it so -- _ will hold numerical index of each Objects will not be equal if the types are different or refer to different objects. It is not ambiguous to anyone who read the first 3 reference manual chapters on the very basic rules of Lua carefully. Write not (co == nil) or co ~= nil. How to convert string to boolean in lua. If (x == condition1 and x == condition2 and x ~= condition3 and x ~= condition4) then Return true End I’m beginning at Lua right now and just want to know if this will work or if there is another way! Your question says that you know Perl. Lua: nested if statements. Part function change() if not lua doesn't use != it uses ~= as could be found with any number of searches online and by looking at any number of lua tutorials/introductions. When I started, I learned to script from tutorials, examining others’ scripts, and just simply But its not possible because it tries to end the second if statement instead of the first, so I have no idea how to solve this in a safe way, any tips or examples would be a nice start. I know that to check if the text is equal to something, you’d do: local TextLabel = script. If I understand your question correctly, I think you mean to use lua_rawequal: int lua_rawequal (lua_State *L, int index1, int index2); Returns 1 if the two values in indices index1 and index2 are primitively equal (that is, without calling metamethods). 1. The above evaluates to if not c == nil Dont work, but the following do: if c == nil then else --stuff end Why?? If your number is in the interval 5-2000, number is greater than or equal 5 and number is smaller than or equal 2000. And not treats its argument as a boolean: 3. And does it the other way around: if its left-hand-side is falsey, it In the else case of the if valid then, you are not returning anything. ~= The == operator in programming has two meanings in mathematical logic. 2. local IsEverythingTrue = true -- the **for** statement is a loop. Master the art of lua string compare with our concise guide. (That you saw all the time on old programs) But an If Statement I'm using doesn't seem to want to work. Share. So change it to f = false. You can also use != instead of ~= Your random values are greater than 1 and adding two numbers greater than 1, will be greater than 1. Your second expression is equivalent to ((not bool) and true) or false which is equivalent to (not bool) or false which is equivalent to not bool, which is clearly not the Short answer. This statement is a very basic, direct order to Lua. Coroutines and metamethods can take you a long way, if you're willing to put some work into it, but I Lua if statement. Skip to main content. My problem is solved ty anyway. The NOT function is a unary logical function. a = true b = false print("a and b = ", (a and b)) Output. npcSpecies) else local npcSpecimen = I know the code is useless and impracticable but I'm in the process of learning to use the lua (luaJIT), c api so please bear with me. For really simple cases, here's an idea: function f(x) return x + 1 end local g = function(y) return y + 1 end f and g are two function that are equal by your definition. The simplest way is to use De Morgan's laws to express the statement 'not one or zero' (which can't be evaluated with binary operators) as 'not one and not zero', which can trivially be written with binary operators: print( "X must be equal To check if a condition is false, you use either not or ~= depending on the value that is being checked. Not to mention the official books and Lua - if statement with two conditions on the How to check if a value is equal or not equal to one of multiple values in Lua? 4. All conditional statements need to have an end keyword to close off the statement. Set up the That's not a bad idea. If every element checks out as equal, the arrays are equal. The Lua if statement is used to execute a block of code only if a certain condition is met. The second is double implication ↔. ") end if str1 < str2 then print(str1 . The "not equal to" condition is true if the thing on the left and right of ~= aren't equal. Commented Oct 8, 2017 at 5:08. Looooong answer. It "daisy chains" on from an if statement and checks another condition if the first is not true. They can be used to direct the flow of a program by specifying code blocks to run depending on the outcome of the expression. Add a comment Making statements based on opinion; back them up with references or personal experience. When the first parameter of or is truthy, it evaluates to that value, if it's not, it evaluates to the second one. The logical operators areand, or, and not. Sign Boolean "not equal to" in Lua (negation of a Boolean conditional) 3. The Built-in String Comparison Operators. There are a few ways to do this. This is very efficient in Lua since tables are hashed by key value which avoids repetitive if then First of all: Operator precedence in Lua is not > and > or. The plain flag allows for the pattern to be ignored and intead be interpreted as a literal. We've created a variable a and initialized it to 100. e. First I have a randomizer that can choose between some plans local phones_price The second example is not really correct. Commented Jun 30, 2012 at 5:37. Switching between two strings like booleans. Hot Network Questions I'm trying to make a UFO in my ROBLOX place, and wanted to create a system that would play an audio when the UFO passes overhead. local c,d = (a~=nil) and 1,1 or 0,0 Lua, if statement idiom fails to return proper boolean. ClassName == ( 'Shirt' or 'Accessory' or 'Pants' or 'CharacterMesh' ) then -- do thing end The statement or condition can contain logic operators and variables. If the condition is true, the code block will be If we want to check if a number is NOT equal to another number, we use a tilde (~). equals() method compares the values of the two operands, but only if the class has implemented this method (which String does), otherwise it behaves the same as == Below, this if-statement is not running since AmountOfPlayers is not equal to minPlayers. As for the first example you provide, i would not recommend doing that as it is not modular or scalable, not in Lua and not in any other How to check if a value is equal or not equal to one of multiple values in Lua? 1. I'm trying to create an if-else statement in Lua script. More on expressions vs statement in this article. equals(str2) str1. If Frame equals 0 you'll assign 1. In fact, it looks like the UNIT_AURA event doesn't actually tell you which aura triggered it. The condition for if statements, while loops, and repeat loops can be any Luau expression or value. A simple version of a switch statement can be implemented using a table to map the case value to an action. PDFprof. Condition has to be true to run the code block after it. function questionGen() local varAnswer = Making statements based on opinion; back them up with references or personal experience. Sign up Lua ""==true equals ""==false. Then in the if statement, we're checking x with 20. Any variable can hold one of the following types: nil, boolean, number, string, table, function, thread, or userdata. Voops. It should be 100 if ttrash has either value and 0 if ttrash does not equal either value. Lua: nested if How can I check if more than 2 values are equal to one another in Lua? lua; Share. This is the first edition, aimed at Lua 5. I would divide var1 and var2 by 9 so that it is normalized. I created a part, inserted an audio into the part, then placed a sc The if statement looks like this to lua: if true then-- Do something end. When I run this code it gets the user input (i. not a statement. not equal to greater than Lua has two statements for condition-controlled loops: the while loop and the repeat loop. Checks if the value of two operands are equal or not, if yes then condition becomes true. Unlike many other languages, Luau considers both zero and the empty string as true. Of course I can write implies(i,j) but I want operator similar to & or | that I can use. Try it out in your Lua compiler! You can modify the conditions to make it even more complicated. e, false is not equal to nil. I am guessing you are trying to generate 15 numbers with no repeats. ("The strings are not equal. NGINX not equal to. The "If" statement is a very common tool found in almost every programming language. Viewed 63k times Making statements based on opinion; back them up with references or personal experience. This means your first expression is equivalent to (bool and false) or true. there are very Making statements based on opinion; back them up with references I actually have not used a unequal operator in my LUA scripts for this game, but i believe while the "natural" syntax of LUA is ~= (as Arnstein86 pointed out) that is quite annoying to write for vast majority of the world, != should work in most LUA interpreters. npcTypes) local npcSpecimen = "" if npcType == "spacebandit" then local npcSpecimen = util. Modified 7 years, 5 months ago. How can I do this? In the terminal, I have printed the matrix a containing nan as all elements and typed a[1][1]=="nan" and a[{{1},{1}}]=="nan" both When I attempt to use elseif, it doesn't work. To further enhance your understanding of control flow in Lua, explore these related topics: Lua While Loops; Lua For Loops; Lua Repeat-Until Loops; Mastering if-else statements is crucial for effective Lua scripting in applications. If the above concepts are totally alien to you, you'll need to spend some time reading real literature, not just copying examples. The condition can be any expression that evaluates to a boolean value. lua, run: luac -l t. This can be really useful in creating your own scripts. Improve this answer. It can also have any number of return statements, and they need not return lists of the same length or meaning. 1 may end up represented as 0. 4. find(subject string, pattern string, optional start position, optional plain flag) Returns the startIndex & endIndex of the substring found. The statement or condition can If statements are a cornerstone of control flow in Lua, providing the ability to make decisions based on dynamic data. io. Overview. Above statement controls opacity of image. Making statements based on opinion; back them up with references or personal experience. Part of why Tecgraf moved to write their own language (first SOL, and then Lua), was that they couldn't really get a hold of SNOBOL and most of the other big names. If Statements. charData is a StringValue to be specific. In Lua script not equal is defined as one of the operator which is helpful for to validate the user input conditions in both front and back end “~=” is the operator symbol for checking the user input conditions that is if the value of the two operands are satisfied the user requirements and comparing it them for performing the application As a Roblox developer, the “not equal to” symbol in traditional Lua code is not as close to psudo code as it could be. 0. Sign up or Boolean "not equal to" in Lua (negation of a Boolean conditional) 2. For example: move = 6 > 3. PICO-8 implements a subset of Lua for writing game cartridges. (A If Statements. Like this (excuse my pseudo-English code): var test = $("#test"). To avoid pitfalls related to nil values, it's wise to: Initialize Variables: Always initialize your variables when declaring them to prevent unintended nil values. When you understand what you get, try modifying parts of it to get something different, or try the effect of replacing "and" with "or". When you set a table variable to nil, it essentially "undeclares" it (removing the entry An operator is a symbol for performing an operation or conditional evaluation. Lua if statements are pretty simple. A function can return any length list. 1000000000000001 (or something like that) and in i will end up never be equal to zero in loop. This article examines Lua if Lua 5. Parent. So basic question is to replicate definition of logical operator & or | from lua. (Partly financial, partly political. Lua Nested if Conditions. How do you use a statement to see if a variable equals a certain string? it says there is an issue with the equal symbol at least think but i'm not very used to lua as i started about a week ago. How to check if a value is greater than one number and less than another number in Lua? 27. So basically I want to make a script that checks if a TextLabel’s Text is NOT equal to something. Those 2 nills checks are there because api sometimes return "nill" and sometimes "nil" and conditional statement is there because i want my method return true or false and not number. Comparing integer variables in LUA. 5+05) return true else return false. 4: If statement syntax error, I can't find anything wrong with my code Hot Network Questions Can we obtain the power set of a finite set without the Axiom of Power Set? Lua also has an if statement for programming the conditions. " comes after especially in conditional statements. If statement in Lua. Such loops will run code, then check if the condition is true. My problem is: I run my code on TouchLua+ on my iPad, it runs nice and smoothly until I get down to the tinput = io. Lua - @aIphabox To add onto what @Nucl3arPlays is saying I would like to note you may run into a similar problem in the future if you happen to expound onto a similar idea. " comes before " . 5. print ("Bring a jacket!") end. String’s have coercion in Lua (5. The print you see is corresponding to the return from the recursive call; it isn't making it out the original call. Also I dont want to check every line, if it works on example currency5, it should stop, just as the first code with the if,elseif and end statements. In mathematical logic, = can only compare values of the domain, so a = b is always a boolean <details><summary>EDIT</summary>I have rewritten the entire post to educate better on conditional statements in specifics. Assume variable A holds 10 and variable B holds 20 then ? Checks if the value of two operands are equal or not, if values are not equal then condition becomes true. An if statement does not need to be followed by any else or elseif statements. This task is rather difficult, if not impossible at all. Further you probably want to think about your logic. Coding Fundamentals. Follow asked Jul 28, 2021 at 2:48. I’m not asking to remove ~=, it’d just change != to ~= in the backend so we have the option to use either. Also your second if statement is missing its closing end. A Lua elseif statement allows for additional boolean expressions to be evaluated in Recently I saw a statement that works in javascript on the internet and I wonder what the meaning of a single equal sign (=) in javascript as I mostly use in if statements is. Specifically, nil is equal only to itself. If an argument isn't false or nil, then the operator evaluates it as true. Since it's a valid object it's not going to be equal to true, false, or nil, it'll be equal to a string with length zero. pplew answered on December 4, 2020 Popularity 10/10 Helpfulness 9/10 Contents ; answer lua not equal; More Related Answers ; if statement lua; lua variable; while loop lua; how to make variables in lua; while loop in lua; Lua if statement; what is a value lua; lua variables; lua if; Can you please explain to me what does " not " do in the if statement with an example? Thanks! Making statements based on opinion; back them up with references or personal experience. But I can't really get it to work :( This is what I have. Statements can contain variables, and all variables have a type, though it can change at any point. Only two add two useful lines. Workspace. For some reason, the if statement isn't executing, meaning the function won't run even if the value doesn't equal Rinzler. That's fine by itself, But, I need/want it to at the same time also check something that's like an "or if" statement, that is. I use this occasionally when writing examples on this sub so I don't have to break the flow of a paragraph for a really short snippet. Best Practices for Handling Nil Avoiding Common Pitfalls. if conditions then local npcType = util. You only return anything in the valid case. What solutions have you tried so far? Googling, Found nothing. How do I go about doing that? doing that not only can be very messy but is also just asking the same thing over and over again slightly modified. This is not too obvious but if you would have something like: local a = 1 function b() print("b") return 1 end function c() Making statements based on opinion; back them up with references or personal experience. Lua: If a number is between 1 and 20. "If" tells the code to do something if a Not ~ (which is used only in ~=, i. Nevertheless, here goes again The == operator tests if the two operands are the same instance. > = {} == "table" false > = {} or and not. then statements run a block of code only when the condition is met. Sign up or Lua - if statement with two conditions on the same variable? 4. Cours LUA Lua if statement not equal PDF , Download,Télécharger ,PDF,Doc,PPT Douments. Improve this question. however, we can still make the if statement do something. By mastering the principles of if statements, including their syntax, If statements in Lua assess conditions and, depending on whether those conditions are true or false, carry out particular code blocks. write("do you w 3 – Statements. . c if my_val ~= nil then --your code here end This code checks if frameAction is nil aswell. It will allow us to operate -- the same way on any number elements in inventory. In this case, I'm trying to check if variable Player. It is popular in the video game industry as a language that can be embedded in a larger game engine. Name is equal to "Player1", "Player2" or "Player3" (example names), and then change Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company It is to be noted that in Lua, zero will be considered as true. Lua provides two fundamental operators for comparing Using Lua in Stormworks Greetings! Welcome to the Lua &quot;Ultimate Beginner's Guide&quot;. the ~= is not equals. Lua is not a very large or complex language, and its syntax is very clearcut. Not Equal To. I wanna check if two tables have the same value in Lua, but didn't find the way. Sign Lua pulls the not stronger than the ==, and interprets that I'm asking whether "a" is a nil value. It returns the opposite of a given Boolean value or the logical test result. which has the advantage of not only being an expression and not being subject to the problem of ifTrue being falsy which means it can handle all cases, but also has the advantage of short-circuiting (not evaluating the other expression). if a<0 then a = 0 end if a<b then return a else return b end if line > MAXLINES then In fact, the result of not is always true or false, and so never equal to nil. 3 Logical Operators. Does Lua have OR comparisons? 4. So depending on what you want to compare you should use In the if statement, you can use elseif and else to define additional conditions to check for: if temperature == 98. ” It would be nice if Roblox’s Luau had syntax sugar to allow us to write != instead of ~=. Otherwise, Lua compares them according to their types. "not equals"), but not. Comparing not equal in Lua uses ~= rather than != (that is from C). If we check if move is true, and then change move to false inside the if-statement, it's not as if we jump out of the if-statement. The operator or returns its first argument if it is not false; otherwise, it returns its second argument: So I have a list in lua which looks something like this hello hello1 hello2 and I want to see if x string is in my list. As if statement is false, the statement within the else block is executed. com Search Engine: Report CopyRight Claim : else elseif end false for function if in local nil not Statements in Lua follow almost the same form as in C and as other conventional [PDF] [PDF] Lua Users Manual - ControlByWeb. 07 and 300) and asked them to implement a unit test that then miserably failed complaining that 21 is not equal 21 Making statements based on opinion; back them up with references or personal experience. So far I have succeeded in defining implies function but that doesn't seem to be of great use. This is probably because "" is an empty string, so Lua probably evaluates it as a string with length of zero. Lua string comparison not I was using an if then statement with the condition being if two values were equal. If Statements if <condition> then <code> end if. Expressions are the section of a statement that, essentially, tell Lua what to string. The rest of this document documents additional syntax used in Luau. If the two ope IF STATEMENTS allow you to use the booleans you just learned about, for example: if 1 == 2 then print ("1 is apparently equal to 2") end Conditionals are used to evaluate statements as true or false. Related Concepts. lua not equal. It's looking for "Heating Up" any time any UNIT_AURA event comes by. It is a comparison fu Skip to main content. About; All I’m looking for is for a way to create a Lua if statement that needs to meet 4 conditions before activating, for example. action or E). Whether you're a seasoned programmer or a newcomer to coding, Lua opens up a new dimension of possi Lua has no switch statement. Lua - Relational Operators - Following table shows all the relational operators supported by Lua language. Introduction In programming languages such as Lua, if statements are important structures that provide programmers exact control over programme flow depending on circumstances. local function arrayEqual(a1, a2) -- Check length, or else the loop isn't valid. Add a comment | 11 Making statements based on opinion; back them up with references or personal experience. Lua If statement evaluation. I understand that not has higher precedence than == Correct. Examples: local iLikeCoffee = true local iDontLikeCoffee = not iLikeCoffee print (iDontLikeCoffee) -- false, because I DO like coffee Code language: Lua (lua) If Statements. Therefore, the message “The number is greater than 50 but less than or equal to 100” is printed. Perhaps it was even several auras at once. (I'm trying to set a flag that indicates whether any process is writing data to disk, as only one process may be permitted to do so. If a statement is very important while programming as it leverages the option of creating a condition where the coder can derive two outputs for the true and false results respectively. The simplest look like this: do_this_code() So only if the boolean expression evaluates true do you do the code. There are 2 main ways to compare Strings: str1. 0. 3 – Logical Operators The logical operators are and, or, and not. This means that questionGen() is always returning true. return expects a list of zero or more return values. No need for extra functions or messing with complex aspects of Lua. See string. if 4 ~= 5 then x = x + 100 * dt end. Actually my problem is, I pass a value 1 to c/c++ which use lua_tonumber to get the value, and i store this value in a double variable, and after sometime, I push the value (lua_pushnumber) to lua, and a < 1 happened: You can use some Lua magic and rewrite Etan Reisner's comment as. Lua - I need a 4 condition if statement. Test if Lua number is integer or float. Here is the code for implies function (not operator). 1. local function hasPlayer(arr, val) for i, v in ipairs(arr) do print(val) print(v) if v == val (Lua) Condition statements not behaving as expected. If it is true, then they run the code again, and they repeat until the condition is false. No, because and or expression always returns one result and the results you see are probably not for the reason you think they are. Thanks for contributing an answer to Stack Overflow! Please be sure to I have a nested if in Lua. Roblox Lua if statement still executing even when the value isn't true. In the if statement, you can use elseif and else to define additional conditions to check for: You can of course reverse a condition by using not like this: if not asleep then eat_food () end -- if not asleep It is considered good programming practice to indent the contents of an if statement, to make it clear what parts are being executed conditionally. a = 1 b = 1 c = 2 if a == b and b == c then print ("they are all equal") else print ("they are not all equal") end Exercise: try out the above. It's just for practice and understanding how Lua is working. Now translate this to Lua. pickRandom(self. local charData = script. Meaning I want it to execute X when A and B and C are met, or if A and D are met, or if A and E are met. find for details. A simple if statement checks a condition and executes a block of code if the condition is true. Does anyone know how to do an and/o Example. Data. We can also assign true or false to a variable with a statement. It is the equivalent in other languages of != Share. If the condition is true, then Luau executes the code Ternary Expressions in Luau - Guide Introduction: As of 2022, the ternary feature has remained an extremely underrated and uncovered feature, that can save lines, and increase readability and elegance in the code. Also returns 0 if any of the indices are not valid. The operator and returns its first argument if it is false; otherwise, it returns its second argument. Often used for this purpose, Lua can be found in everything from photo editing applications to used as an internal scripting. if 1 == 2 then print ("1 is apparently equal to 2") else print ("1 isnt equal to 2") end Disclaimer: I have no experience with lua, this is an educated guess. Why isn't this code changing the variable to True Or False. If statement in Lua is just like other programming languages including C, C++, Python. You mean to return getNumbers(). Lua strings maintain their length internally, so you wouldn't have to count characters. a ? b : c. If a value isn't false or nil, then Luau evaluates it as true in conditional statements. However you can't compare a sequence like that. because (a) if you want to decrease i in loop third parameter should be negative , (b) you really should not use float or double in for loop because of precision\representation: 0. Logical operators return values depending on the boolean values of the given arguments. – Alexander Gladysh. Why isn't this code changing the variable to First off, I know this is a messy, unorganized pile of Lua, but I'm still learning, so please forgive me. As i wrote before this solved my problem strmatch(val,"%d") ,I needed to check if value in string are digits. Lua lacks a C-style switch statement. If any element is not equal, you know right away that the arrays aren't equal. If statements in Lua assess conditions and, depending on whether those conditions are true or false, carry out particular code blocks. x additions; for details please refer to compatibility section. Defining logical operator implies in lua. It's not idiomatic, but Lua also accepts semicolons for statement separation if you want to do this with more than one thing in a line, so if x == y then foo=1; bar=2 else foo=2=; bar=1 end works as well. Lua - if statement with two conditions on the same variable? 38. This is the correct syntax: if x >= 100 and x < 200 then -- your code end Just remember that most programming languages (with Python being a notable exception) don't support chained comparison operators and you have to explicitly compare twice and combine the results of the comparisons with a logical and. number >= 5 and number <=2000 If you're dealing with integer numbers only you may of Short answer: no, that's just not how loops work. read(), whether I type 'attack' or 'run away' I end up with an "that is not a valid command" printed on the screen, infinitely. How do I use multiple If's in Lua? 3. e add) but then does nothing and skips to the end of the code. Is there a way I can reduce this in-a-row kind of repeating Lua conditions? Related. Follow Making statements based on opinion; back them up with references or personal experience. 8. I'm trying to make a 'simple' Y/N answer choice thing. Long answer: Technically, you could do this with lots of magic, but it wouldn't look pretty. I even print out the variable and it is How to do not equal to? – Umair Javaid. however, I'm getting the same output regardless of the input I provide. Be very careful not to mix it up with =, which assigns new values to objects like variables. The basic if statement tests its condition. Like control structures, all logical operators consider false and nil as false and anything else as true. Commented Jul 5, 2018 at 21:52. ; Return Statements: Be cautious in functions to ensure all paths return meaningful values rather than nil. Introduction to Lua not equal. Ask Question Asked 7 years, 5 months ago. I'd like to perform an atomic GET in Redis, and if the value returned is equal to some expected value, I'd like to do a SET, but I want to chain all of this together as one atomic operation. These conditions are typically expressions that evaluate to a As a Roblox developer, the “not equal to” symbol in traditional Lua code is not as close to psudo code as it could be. Lua has no equivalent of Python's in operator, but if you know what container type you want to emulate, it's easy to write a function for it. To learn more, Lua/torch multiplication of 1D and 2D tensors. Like that, not equal(~=) is one of the relational operators and it returns only the boolean set of statements like true and false. This does not work in a case of "value = false and true or false". provided that b is not false. Yep, this is the answer. 19. Text == "Example" then end I however, want something like this, but the script would instead check if the text is not “Example”. Rather than (tiger) being interpreted as a pattern capture group matching for tiger, it instead looks for (tiger) within a string. Lua: attempt to compare boolean with number. The problem with the above, however, is that it's certainly not efficient! If 'userinput' is "Hi" it is not "Bye", so our computer shouldn't have to check if it's "Bye" after determining that it's "Hi"!. CharacterData local active = game. Lua is a dynamically type-based language. Types of If Statements in Lua Simple If Statement. Unlike other scripting languages, Luau considers both zero and the empty string as true. The syntax of the if statement is as follows: lua if condition then-- Code to execute if condition is true end. Lua compares tables, userdata, and functions by reference, that is, two such values are considered equal only if they are the very same object. An if statement tests its condition and executes its then-part or its else-part accordingly. But I put it in a infinite loop to stop this but it is still skipping the code in the if statements. Learn how to code if statements in Roblox Lua. val Learning Lua Part 1: Variables and Conditional Statements Part 2: Functions and Tables Part 3: Objects and Looping Lua is a multi-paradigm scripting language originally designed to be embedded as part of other, existing programs. Steps: Make a new column D and give it the heading Compare Collection. Add Answer . But Lua also interns strings, so checking for equality doesn't require looking at characters, either; you just check if the objects are the same. I want to break a for loop as soon as the matrix's first element becomes nan to understand the problem. How to check if a value is greater than one number and less than another number in Lua? 4. 6 then trace In Lua, the only values that are not evaluated as true are false and nil. The true argument ensures that the substring is treated literally and not as a pattern. not is for true/false values and ~= is for comparing strings or numbers. Also, you wrote =< for "greater than or equal to". str. Lua, if statement idiom fails to return proper boolean. I suppose on second thought A != B mathematically means factorial of A is equal to B so maybe I can forgive Lua being written in C but not just using the C style != operator :p – Brant Sterling Wedel. In Lua both nil and the boolean value false represent false in a logical expression. in our case, when ran it wont print anything because obviously 1 isnt equal to 2 also, always use == instead of = when comparing numbers, if you use = it will think you are declaring a variable. lua The output is: According to the Lua sources, Lua uses a simple equality operator when comparing doubles, these numbers (0. Back to Guides. Fixed the example in answer. yes. I would advise reading Programming in Lua to make sure you understand the very basics. find not working with decimal. Lua - if statement Using lua on watchmaker. Of course, as noted by others (and as practiced in languages older than Lua), the solution to your real problem is to change representation. The . There should be a "close question" option dedicated to it. Also you will need to add a line to check if varAnswer say greater than 1 (0. If I leave out the or and only test one value it works fine. Logical. While in other languages, the logical operators return either true or false, Lua (and some other languages) does something more clever:. This set includes assignments, control Closures created at different times but with no detectable differences may be classified as equal or not (depending on internal caching details). This comes up at least once per day. If Statements in Lua. I was wondering if I could get some help with this small script I tested. qqtwm oqe igpk kwcen iyvqkw mdtwx byxkg dyszgfko iairc cyb