A bit confused. Why does this output 0?

Question

var x, y = 0;

function change () {
for ( x = 5; x < 10; x++) {
++y;
}
}

alert (y);

Answer 1

In your code, you have set your for loop inside of a function change. The problem is that you're not calling the function, therefore it is not running and the value of y is just going to default to 0.

Answer 2

I don't know much JavaScript, but it looks like you've forgotten to call the function.
Out of curiosity, what does '++y' do?

Answer 3

++y is something that is called a pre increment. What it does is it takes the value of y and increments it before using its value, the exact opposite of what y++ would do.

Answer 4

@immortal, I think I get it now.

There are 2 code blocks and the ++y is within the second code block.

For the second code block to read the y variable, there needs to be a y variable in first code block, whereas the y variable is only present in global scope & not the first functional scope.

correct me if I'm wrong, please.

Answer 5

@Brian I'm pretty sure that isn't the case, this should work just fine if you call the change()function.

@Thanks, so it seems that it only changes the value it returns. Then it shouldn't make a difference in this case right?