Append string vs join array

JavaScript performance comparison

Revision 12 of this test case created

Preparation code

 
<script>
  Benchmark.prototype.setup = function() {
    var i = 0,
        str = '',
        arr = [],
        w1 = 'brown',
        w2 = 'jumped',
        w3 = 'lazy';
  };
</script>

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Testing in unknown unknown
Test Ops/sec
array join bad
 
arr = [];
for (var i = 0; i < 100; i++) {
  arr[i++] = 'Quick ';
  arr[i++] = w1;
  arr[i++] = ' fox ';
  arr[i++] = w2;
  arr[i++] = ' over the ';
  arr[i++] = w3;
  arr[i++] = ' dog. ';
  arr.join('');
}
 pending…
String contcat
 
str = '';
for (var i = 0; i < 100; i++) {
  str += 'Quick ';
  str += w1;
  str += ' fox ';
  str += w2;
  str += ' over the ';
  str += w3;
  str += ' dog. ';
}
 pending…
Array join #2
 
arr = [];
for (var j = 0; j < 100; j++) {
  arr.push('Quick ', w1, ' fox ', w2, ' over the ', w3, ' dog. ');
}
arr.join();
 pending…

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