Javascript change for loop variable from within the loop - Stack Overflow

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I have a for loop like so

for (var i = 0; i < 100; i += 4) {
    // code with i;
}

I would like to change the value of i to a certain value from within the loop. I am aware you could use continue to change the value of i after evaluating the final-expression, but what if I wanted to change the value of i to something more specific like 40?

Here's one of my attempts

loop:
for (var i = 0; i < 100; i += 4) {
    for (var i = 0; i <= 40; i++) {
        continue loop;
    }
}

Is there a better way of doing this?

I have a for loop like so

for (var i = 0; i < 100; i += 4) {
    // code with i;
}

I would like to change the value of i to a certain value from within the loop. I am aware you could use continue to change the value of i after evaluating the final-expression, but what if I wanted to change the value of i to something more specific like 40?

Here's one of my attempts

loop:
for (var i = 0; i < 100; i += 4) {
    for (var i = 0; i <= 40; i++) {
        continue loop;
    }
}

Is there a better way of doing this?

• javascript
• variables
• for-loop
• continue

Share Improve this question Follow asked Jan 1, 2014 at 21:02 PatrickPatrick 1,42822 gold badges1919 silver badges3737 bronze badges 3

• Why can't you just assign it the value you want? It's just another variable after all. Just make sure you don't set it in such a way that you'll infinitely loop. – cookie monster Commented Jan 1, 2014 at 21:03
• 1 I have a feeling that this may be an X/Y Problem. – cookie monster Commented Jan 1, 2014 at 21:05
• I see that I could've reassigned it now. And yes this is one question I'm looking an answer to in order to solve a bigger problem. – Patrick Commented Jan 1, 2014 at 21:23

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2 Answers 2

Sorted by: Reset to default 3

Just change i directly:

for (var i = 0; i < 100; i += 4) {
    i = 15000;
}

This would exit the loop immediately, but you could do whatever you wanted.

You should read up on function scope to understand how this stuff works. For loops are bit different from functions in that they're a language construct but the same theory of scope holds true.

The scope of increment variable is always available inside the loop block, this allows you to access increment variable inside the loop block.

for (var i = 0; i < 100; i += 4) {
    if (condition)  i = 40 ;
    /* put any condition to avoid the infinite loop and continue with your rest of code */
}

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