Run results for: js Count the occurences of an item in an array

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/53.0.2785.116 Safari/537.36

Browser: Chrome 53

Operating system: Mac OS X 10.11.6

Device Platform: Other

Date tested: 7 years ago

Test name	Executions per second
arr.filter	743177.9 Ops/sec
for	1740220.0 Ops/sec

Tests:

arr.filter
count = function(arr, item) { return arr.filter(function(x){return x==item}).length } count([1,2,3,2,4,2], 2);
for
count = function(arr, item) { var count = 0; for(var i = 0; i < arr.length; ++i){ if(arr[i] == item) count++; } return count } count([1,2,3,2,4,2], 2);
arr.reduce
count = function(arr, item) { return arr.reduce(function(total,x){return x==item ? total+1 : total}, 0); } count([1,2,3,2,4,2], 2);
regex
count = function(arr, item) { var regex = new RegExp('[^'+item+']+', 'g'); return String(arr).replace(regex,'').length } count([1,2,3,2,4,2], 3);
indexOf
count = function(arr, item) { var count= 0, i; while((i= arr.indexOf(item, i))!= -1){ ++count; ++i; } return count; } count([1,2,3,2,4,2], 2);