Conditionals

A conditional determines whether or not certain blocks of code will run. A conditional checks the value of an expression, called the condition. If the condition is false, then the code block within the conditional will be skipped. Otherwise, the code block will be run.

Conditionals are used to control the flow of the execution of code within a program.

if Conditionals

A basic if conditional in Luau is given as follows:

if <condition> then
  <code block>
end

Examples of basic if conditionals

if true then  --code block ran
  print("code block ran")
end

if false then  --no output
  print("code block ran")
end

if "chicken" then  --code block ran
  print("code block ran")
end

else and elseif

To augment the basic if conditional, elseif can be used to check additional conditions if the first condition is false. Also, the else keyword can be used as a catchall to run a code block if all previous conditions were false.

if <condition 1> then
  <code block 1>
elseif <condition 2> then
  <code block 2>
else
  <code block 3>
end

In the code above, condition 1 is checked first. condition 2 is checked only if condition 1 is false. If the first two conditions are both false, then code block 3 will be executed.

else and elseif examples

The following examples illustrate conditionals that use else and elseif.

if "tony" == "paulie" then  --madone!
  print("ooh!")
elseif "silvio" == "junior" then
  print("dooh!")
else
  print("madone!")
end

if 3 >= 4 then  --dooh!
  print("ooh!")
elseif 23 then
  print("dooh!")
else
  print("madone!")
end

if "AJ" == "AJ" and 3 < 10 then  --ooh!
  print("ooh!")
else
  print("dooh!")
end