Revisions to Loop through an array in JavaScript

Active reading. Dressed the naked link.

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edited Oct 30, 2020 at 6:59

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Use the whilewhile loop...

var i=0i = 0, item, items = ['one', 'two', 'three'];
while(item = items[i++]){
    console.log(item);
}

It logs: 'one','two' 'two','three' and 'three'

And for the reverse order, an even more efficient loop:

var items = ['one', 'two', 'three'], i = items.length;
while(i--){
    console.log(items[i]);
}

It logs: 'three','two' 'two','one' and 'one'

Or the classical for loop:

var items = ['one', 'two', 'three']
for(var i=0, l = items.length; i < l; i++){
    console.log(items[i]);
}

It logs: 'one','two','three'

Reference: http://www.sitepoint.com/google-closure-how-not-to-write-javascript/ Google Closure: How not to write JavaScript

Use the while loop...

var i=0, item, items = ['one','two','three'];
while(item = items[i++]){
    console.log(item);
}

logs: 'one','two','three'

And for the reverse order, an even more efficient loop

var items = ['one','two','three'], i = items.length;
while(i--){
    console.log(items[i]);
}

logs: 'three','two','one'

Or the classical for loop

var items = ['one','two','three']
for(var i=0, l = items.length; i < l; i++){
    console.log(items[i]);
}

logs: 'one','two','three'

Reference: http://www.sitepoint.com/google-closure-how-not-to-write-javascript/

Use the while loop...

var i = 0, item, items = ['one', 'two', 'three'];
while(item = items[i++]){
    console.log(item);
}

It logs: 'one', 'two', and 'three'

And for the reverse order, an even more efficient loop:

var items = ['one', 'two', 'three'], i = items.length;
while(i--){
    console.log(items[i]);
}

It logs: 'three', 'two', and 'one'

Or the classical for loop:

var items = ['one', 'two', 'three']
for(var i=0, l = items.length; i < l; i++){
    console.log(items[i]);
}

It logs: 'one','two','three'

Reference: Google Closure: How not to write JavaScript

added 2 characters in body

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edited Feb 14, 2014 at 19:26

Timo Huovinen

55k
33
157
148

Use the while loop...

var i=0, item, items = ['one','two','three'];
while(item = items[i++]){
    console.log(item);
}

logs: 'one','two','three'

And for the reverse order, an even more efficient loop

var items = ['one','two','three'], i = items.length;
while(i--){
    console.log(items[i]);
}

logs: 'three','two','one'

Or the classical for loop

var items = ['one','two','three']
for(var i=0, l=itemsl = items.length; i < l; i++){
    console.log(items[i]);
}

logs: 'one','two','three'

Reference: http://www.sitepoint.com/google-closure-how-not-to-write-javascript/

Use the while loop...

var i=0, item, items = ['one','two','three'];
while(item = items[i++]){
    console.log(item);
}

logs: 'one','two','three'

And for the reverse order, an even more efficient loop

var items = ['one','two','three'], i = items.length;
while(i--){
    console.log(items[i]);
}

logs: 'three','two','one'

Or the classical for loop

var items = ['one','two','three']
for(var i=0, l=items.length; i < l; i++){
    console.log(items[i]);
}

logs: 'one','two','three'

Reference: http://www.sitepoint.com/google-closure-how-not-to-write-javascript/

Use the while loop...

var i=0, item, items = ['one','two','three'];
while(item = items[i++]){
    console.log(item);
}

logs: 'one','two','three'

And for the reverse order, an even more efficient loop

var items = ['one','two','three'], i = items.length;
while(i--){
    console.log(items[i]);
}

logs: 'three','two','one'

Or the classical for loop

var items = ['one','two','three']
for(var i=0, l = items.length; i < l; i++){
    console.log(items[i]);
}

logs: 'one','two','three'

Reference: http://www.sitepoint.com/google-closure-how-not-to-write-javascript/

Copy edited. Removed meta information.

Source Link

edited Aug 10, 2013 at 8:21

Peter Mortensen

31.3k
22
109
132

Can't beleive no one mentioned usingUse the while loop...

var i=0, item, items = ['one','two','three'];
while(item=items[i++]item = items[i++]){
    console.log(item);
}

logs: 'one','two','three'

andAnd for the reverse order, an even more efficient loop

var items = ['one','two','three'], i=itemsi = items.length;
while(i--){
    console.log(items[i]);
}

logs: 'three','two','one'

orOr the classical forfor loop

var items = ['one','two','three']
for(var i=0, l=items.length; i < l ;l; i++){
    console.log(items[i]);
}

logs: 'one','two','three'

referenceReference: http://www.sitepoint.com/google-closure-how-not-to-write-javascript/

Can't beleive no one mentioned using the while loop...

var i=0,item,items = ['one','two','three'];
while(item=items[i++]){
    console.log(item);
}

logs: 'one','two','three'

and for the reverse order, an even more efficient loop

var items = ['one','two','three'], i=items.length;
while(i--){
    console.log(items[i]);
}

logs: 'three','two','one'

or the classical for loop

var items = ['one','two','three']
for(var i=0,l=items.length; i < l ; i++){
    console.log(items[i]);
}

logs: 'one','two','three'

reference: http://www.sitepoint.com/google-closure-how-not-to-write-javascript/

Use the while loop...

var i=0, item, items = ['one','two','three'];
while(item = items[i++]){
    console.log(item);
}

logs: 'one','two','three'

And for the reverse order, an even more efficient loop

var items = ['one','two','three'], i = items.length;
while(i--){
    console.log(items[i]);
}

logs: 'three','two','one'

Or the classical for loop

var items = ['one','two','three']
for(var i=0, l=items.length; i < l; i++){
    console.log(items[i]);
}

logs: 'one','two','three'

Reference: http://www.sitepoint.com/google-closure-how-not-to-write-javascript/

Source Link

created Jan 5, 2012 at 9:15

Timo Huovinen

55k
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157
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