What is the difference between repeat and while on the moon?

Basically, repeat is equivalent to do ... while of other languages.

In while , you are giving the condition to enter the loop . If the condition is false, operations performed within the framework will not be performed at any time.

local i = 1
while a[i] do
  print(a[i])
  i = i + 1
end

In repeat , you give the condition on output, using until . At least once, the statements will be executed inside the loop .

repeat
  line = os.read()
until line ~= ""
print(line)

Interesting to note this conceptual difference:

• while , the true condition does that you remain within the loop .

• In until the true condition makes that you exit from within the loop .

. until " is " repeat ... until ".     

Think as if while was "while" and repeat until was "repeat until". For example

repeat
wait()
num=num+1
until var==true

This loop will repeat until var==true

now

while var==true do
wait()
num=num+1
end

will loop as var==true , and will do this until you stop the game, other than repeat , which runs only once. I hope this has helped;)