Revisions to Loop through an array in JavaScript

Commonmark migration

Source Link

edited Jun 20, 2020 at 9:12

1
1

##The most elegant and fast way

The most elegant and fast way

var arr = [1, 2, 3, 1023, 1024];
for (var value; value = arr.pop();) {
    value + 1
}

http://jsperf.com/native-loop-performance/8

Edited (because I was wrong)

Comparing methods for looping through an array of 100000 items and do a minimal operation with the new value each time.

http://jsben.ch/#/BQhED

Preparation:

<script src="//code.jquery.com/jquery-2.1.0.min.js"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/underscore.js/1.6.0/underscore-min.js"></script>
<script>
    Benchmark.prototype.setup = function() {
        // Fake function with minimal action on the value
        var tmp = 0;
        var process = function(value) {
            tmp = value; // Hold a reference to the variable (prevent engine optimisation?)
        };
        
        // Declare the test Array
        var arr = [];
        for (var i = 0; i < 100000; i++)
            arr[i] = i;
    };
</script>

Tests:

<a href="http://jsperf.com/native-loop-performance/16" 
   title="http://jsperf.com/native-loop-performance/16"
><img src="http://i.imgur.com/YTrO68E.png" title="Hosted by imgur.com" /></a>

##The most elegant and fast way

var arr = [1, 2, 3, 1023, 1024];
for (var value; value = arr.pop();) {
    value + 1
}

http://jsperf.com/native-loop-performance/8

Edited (because I was wrong)

Comparing methods for looping through an array of 100000 items and do a minimal operation with the new value each time.

http://jsben.ch/#/BQhED

Preparation:

<script src="//code.jquery.com/jquery-2.1.0.min.js"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/underscore.js/1.6.0/underscore-min.js"></script>
<script>
    Benchmark.prototype.setup = function() {
        // Fake function with minimal action on the value
        var tmp = 0;
        var process = function(value) {
            tmp = value; // Hold a reference to the variable (prevent engine optimisation?)
        };
        
        // Declare the test Array
        var arr = [];
        for (var i = 0; i < 100000; i++)
            arr[i] = i;
    };
</script>

Tests:

<a href="http://jsperf.com/native-loop-performance/16" 
   title="http://jsperf.com/native-loop-performance/16"
><img src="http://i.imgur.com/YTrO68E.png" title="Hosted by imgur.com" /></a>

The most elegant and fast way

var arr = [1, 2, 3, 1023, 1024];
for (var value; value = arr.pop();) {
    value + 1
}

http://jsperf.com/native-loop-performance/8

Edited (because I was wrong)

Comparing methods for looping through an array of 100000 items and do a minimal operation with the new value each time.

http://jsben.ch/#/BQhED

Preparation:

<script src="//code.jquery.com/jquery-2.1.0.min.js"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/underscore.js/1.6.0/underscore-min.js"></script>
<script>
    Benchmark.prototype.setup = function() {
        // Fake function with minimal action on the value
        var tmp = 0;
        var process = function(value) {
            tmp = value; // Hold a reference to the variable (prevent engine optimisation?)
        };
        
        // Declare the test Array
        var arr = [];
        for (var i = 0; i < 100000; i++)
            arr[i] = i;
    };
</script>

Tests:

<a href="http://jsperf.com/native-loop-performance/16" 
   title="http://jsperf.com/native-loop-performance/16"
><img src="http://i.imgur.com/YTrO68E.png" title="Hosted by imgur.com" /></a>

removed unnecessary comment from editor

Source Link

edited Oct 17, 2016 at 23:08

Emile Bergeron

17.3k
5
84
130

##The most elegant and fast way

var arr = [1, 2, 3, 1023, 1024];
for (var value; value = arr.pop();) {
    value + 1
}

http://jsperf.com/native-loop-performance/8

Edited (because I was wrong)

Comparing methods for looping through an array of 100000 items and do a minimal operation with the new value each time.

http://jsben.ch/#/BQhED ! (edited for providing working benchmark)

Preparation:

<script src="//code.jquery.com/jquery-2.1.0.min.js"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/underscore.js/1.6.0/underscore-min.js"></script>
<script>
    Benchmark.prototype.setup = function() {
        // Fake function with minimal action on the value
        var tmp = 0;
        var process = function(value) {
            tmp = value; // Hold a reference to the variable (prevent engine optimisation?)
        };
        
        // Declare the test Array
        var arr = [];
        for (var i = 0; i < 100000; i++)
            arr[i] = i;
    };
</script>

Tests:

<a href="http://jsperf.com/native-loop-performance/16" 
   title="http://jsperf.com/native-loop-performance/16"
><img src="http://i.imgur.com/YTrO68E.png" title="Hosted by imgur.com" /></a>

##The most elegant and fast way

var arr = [1, 2, 3, 1023, 1024];
for (var value; value = arr.pop();) {
    value + 1
}

http://jsperf.com/native-loop-performance/8

Edited (because I was wrong)

Comparing methods for looping through an array of 100000 items and do a minimal operation with the new value each time.

http://jsben.ch/#/BQhED ! (edited for providing working benchmark)

Preparation:

<script src="//code.jquery.com/jquery-2.1.0.min.js"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/underscore.js/1.6.0/underscore-min.js"></script>
<script>
    Benchmark.prototype.setup = function() {
        // Fake function with minimal action on the value
        var tmp = 0;
        var process = function(value) {
            tmp = value; // Hold a reference to the variable (prevent engine optimisation?)
        };
        
        // Declare the test Array
        var arr = [];
        for (var i = 0; i < 100000; i++)
            arr[i] = i;
    };
</script>

Tests:

<a href="http://jsperf.com/native-loop-performance/16" 
   title="http://jsperf.com/native-loop-performance/16"
><img src="http://i.imgur.com/YTrO68E.png" title="Hosted by imgur.com" /></a>

##The most elegant and fast way

var arr = [1, 2, 3, 1023, 1024];
for (var value; value = arr.pop();) {
    value + 1
}

http://jsperf.com/native-loop-performance/8

Edited (because I was wrong)

Comparing methods for looping through an array of 100000 items and do a minimal operation with the new value each time.

http://jsben.ch/#/BQhED

Preparation:

<script src="//code.jquery.com/jquery-2.1.0.min.js"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/underscore.js/1.6.0/underscore-min.js"></script>
<script>
    Benchmark.prototype.setup = function() {
        // Fake function with minimal action on the value
        var tmp = 0;
        var process = function(value) {
            tmp = value; // Hold a reference to the variable (prevent engine optimisation?)
        };
        
        // Declare the test Array
        var arr = [];
        for (var i = 0; i < 100000; i++)
            arr[i] = i;
    };
</script>

Tests:

<a href="http://jsperf.com/native-loop-performance/16" 
   title="http://jsperf.com/native-loop-performance/16"
><img src="http://i.imgur.com/YTrO68E.png" title="Hosted by imgur.com" /></a>

replaced old not working jsperf link by a working benchmark

Source Link

edit approved Oct 17, 2016 at 23:08

EscapeNetscape

2.9k
1
36
32

##The most elegant and fast way

var arr = [1, 2, 3, 1023, 1024];
for (var value; value = arr.pop();) {
    value + 1
}

http://jsperf.com/native-loop-performance/8

Edited (because I was wrong)

Comparing methods for looping through an array of 100000 items and do a minimal operation with the new value each time.

http://jsperf.com/native-loop-performance/16 http://jsben.ch/#/BQhED ! (edited for providing working benchmark)

Preparation:

<script src="//code.jquery.com/jquery-2.1.0.min.js"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/underscore.js/1.6.0/underscore-min.js"></script>
<script>
    Benchmark.prototype.setup = function() {
        // Fake function with minimal action on the value
        var tmp = 0;
        var process = function(value) {
            tmp = value; // Hold a reference to the variable (prevent engine optimisation?)
        };
        
        // Declare the test Array
        var arr = [];
        for (var i = 0; i < 100000; i++)
            arr[i] = i;
    };
</script>

Tests:

<a href="http://jsperf.com/native-loop-performance/16" 
   title="http://jsperf.com/native-loop-performance/16"
><img src="http://i.imgur.com/YTrO68E.png" title="Hosted by imgur.com" /></a>

##The most elegant and fast way

var arr = [1, 2, 3, 1023, 1024];
for (var value; value = arr.pop();) {
    value + 1
}

http://jsperf.com/native-loop-performance/8

Edited (because I was wrong)

Comparing methods for looping through an array of 100000 items and do a minimal operation with the new value each time.

http://jsperf.com/native-loop-performance/16 !

Preparation:

<script src="//code.jquery.com/jquery-2.1.0.min.js"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/underscore.js/1.6.0/underscore-min.js"></script>
<script>
    Benchmark.prototype.setup = function() {
        // Fake function with minimal action on the value
        var tmp = 0;
        var process = function(value) {
            tmp = value; // Hold a reference to the variable (prevent engine optimisation?)
        };
        
        // Declare the test Array
        var arr = [];
        for (var i = 0; i < 100000; i++)
            arr[i] = i;
    };
</script>

Tests:

<a href="http://jsperf.com/native-loop-performance/16" 
   title="http://jsperf.com/native-loop-performance/16"
><img src="http://i.imgur.com/YTrO68E.png" title="Hosted by imgur.com" /></a>

##The most elegant and fast way

var arr = [1, 2, 3, 1023, 1024];
for (var value; value = arr.pop();) {
    value + 1
}

http://jsperf.com/native-loop-performance/8

Edited (because I was wrong)

Comparing methods for looping through an array of 100000 items and do a minimal operation with the new value each time.

http://jsben.ch/#/BQhED ! (edited for providing working benchmark)

Preparation:

<script src="//code.jquery.com/jquery-2.1.0.min.js"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/underscore.js/1.6.0/underscore-min.js"></script>
<script>
    Benchmark.prototype.setup = function() {
        // Fake function with minimal action on the value
        var tmp = 0;
        var process = function(value) {
            tmp = value; // Hold a reference to the variable (prevent engine optimisation?)
        };
        
        // Declare the test Array
        var arr = [];
        for (var i = 0; i < 100000; i++)
            arr[i] = i;
    };
</script>

Tests:

<a href="http://jsperf.com/native-loop-performance/16" 
   title="http://jsperf.com/native-loop-performance/16"
><img src="http://i.imgur.com/YTrO68E.png" title="Hosted by imgur.com" /></a>

Copy edited. Used different formatting (Markdown-oriented).

Source Link

edited Jun 22, 2014 at 22:13

Peter Mortensen

31.3k
22
109
132

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More accurate comparison of each methods

Source Link

edited May 16, 2014 at 21:59

molokoloco

4.6k
2
34
28

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Source Link

created Mar 8, 2014 at 2:06

molokoloco

4.6k
2
34
28

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The most elegant and fast way

Edited (because I was wrong)

Edited (because I was wrong)

The most elegant and fast way

Edited (because I was wrong)

Edited (because I was wrong)

Edited (because I was wrong)

Edited (because I was wrong)

Edited (because I was wrong)

Edited (because I was wrong)

Edited (because I was wrong)