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iOS

Posted by Alex Parsons
Alex Parsons
Courses Plus Student 214 Points

Using While Loops

Here is an example of the while loop that i am attempting to write.

let y = 0 y++ while x <= 10 { println("Repeat") }

It worked when i took out the y++ postfix unary but it crashed my computer. So i wanted to print it out only 10 times. For some reason it is not working

I get two errors the first one for y++ it says "cannot invoke '++' with an argument of type 'int'. The second error i get states "use of unresolved identifier 'x'."

Thanks for the help in advance.

1 Answer

Stone Preston
Stone Preston
42,016 Points

you need to increment inside the loop. also you need to use y, not x. you have not defined a variable x which is why you get that error:

var y = 0 
while y < 10 {
 println("Repeat") 
 y++

}

in the loop above, you set y to 0. then you say "while y is less than 10, print out "repeat" and then increment y by 1. so the loop checks to make sure that y is less than 10, then runs the code in the loop body. then it checks again, then runs it again etc etc until y is no longer less than 10. at that point the loop stops

Alex Parsons
Alex Parsons
Courses Plus Student 214 Points

hmm for some reason i am still getting the error for the y++. It still says "cannot invoke '++' with an argument of type 'int'. "

Stone Preston
Stone Preston
42,016 Points

woops, you need to declare y as a var, not a constant. if its a constant you cant increment it