Hello, person reading this post. I’ve been wondering about the usage of and when setting variables and properties. For example:
local var = 1 and 2
local vec = Vector3.new(0,0,0)
somePart.Position = vec and Vector3.new(255,255,255)
-- what is the logic behind?
and do, on non-loop situations, such as:
do
print("???")
end
-- is there anything different than not having "do end"?
Seen those used in some places, but I wasn’t able to find how it works out by myself.
Thanks in advance!
I don’t know why someone did that. a and b evaluates to a if a is falsey, b otherwise. var would get 2 and somePart.Position gets Vector3.new(255, 255, 255).
The difference is it creates a new scope. You can declare locals in that do ... end and they won’t be accessible to the outer scope.
do
local x = 5
print(x) -- 5
end
print(x) -- nil
Does that mean and would be the contrary to or?
local a = false or 1 -- if first value is false/nil, the second value is valid(1)
local b = false and 1 -- if first value is false/nil, the first value is valid(false)
Yes, that would be correct. false or 1 evaluates to 1 since false is falsey. false and 1 evaluates to false.
do is commonly followed by conditional staments in loops (off the top of my head thats the only place i really use them) like:
while chicken == not fat do
feed the chicken
and
is used to usually check that two conditions are met before executing a block of code e.g:
if chicken == fat and chicken == eating then
kill it before it gets to fat lol
it wont kill it if its just fat or if its just eating it has to be doing both
the or statement on the other hand
will execute the block of code if either of the conditions are met e.g:
if chicken == fat or chicken == eating then
kill it because its either fat or its eating
it will execute if the chicken is fat or if its eating one or the other and it will do it
You haven’t read the question correctly.
You gave me an example of usage on an if statement, not setting variables/properties.
Here, you gave me an example with while, which is a loop.
Though, I do appreciate the reply.
have u got a working example of any code that actually uses
and when setting a variable because i havent seen it before
people might use:
local pie, chicken, turkey = game.workspace.pie, game.workspace.chicken, game.workspace.turkey
not
local pie, chicken, turkey = game.workspace.pie and game.workspace.chicken and game.workspace.turkey
in other higher level languages like python you would use a simillar thing to do you would use a colon however in lua the “do” / “:” is automatically added in, in a sense
it would theoretically go after an else statement or an if statment but you only put them after a loop is declared in lua so no the “do”'s are autmatically added in (invisibly is a way to think about it) now im not 100% sure on this but thats all there really is to know about it
On Creating A Furniture Placement System, there is this line:
local axis = (math.abs(dot) == 1) and Vector3.new(-dot, 0, 0) or up
It works like this:
-- result = *statement* and *if it's true* or *if it's false*
local statementIsTrue = true and 'Is true' or 'Is false'
print(statementIsTrue) -- "Is true"
local statementIsTrue = false and 'Is true' or 'Is false'
print(statementIsTrue) -- "Is false"
You can use this instead of using if statements for simple stuff.
For example:
local a = 1
local b = 2
local higherNumber
if a > b then
higherNumber = a
else
higherNumber = b
end
That could be converted to:
local a = 1
local b = 2
local higherNumber = (a > b) and a or b
Not exactly, if the second operand evalulates to false (false/nil) it’ll return the third operand.
Lua example
print(true and nil or 2) --> 2
C example (to demostrate the tenary conditional operator because Lua don’t have it)
#include <stdio.h>
int main() {
printf("%d\n", 1 ? 0 : 2); /* 0 */
printf("%d", 1 && 0 || 2); /* 2 */
return 0;
}