Run results for: spreadArray

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/51.0.2704.79 Safari/537.36 Edge/14.14393

Browser: Chrome 51

Operating system: Windows

Device Platform: Other

Date tested: 7 years ago

Test name	Executions per second
ComparisonAndConcat	65359.0 Ops/sec
Concat	64054.0 Ops/sec
Comparison	298072.3 Ops/sec
Pop	380983.8 Ops/sec
Shift	387946.3 Ops/sec
Slice	336216.8 Ops/sec
TailSlice	317854.3 Ops/sec
Slice2	358907.6 Ops/sec
For	678228.1 Ops/sec
ForReverse	336988.9 Ops/sec
ForComparison	720727.8 Ops/sec
ForWithInit	718744.6 Ops/sec

Script Preparation code:

var testArray = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'.split('');
var delim = {'a': 1};

function spreadArrayComparisonAndConcat(array, delim) {
    return array.reduce(function (result, item, i) {
        return i === 0 ? result.concat(item) : result.concat(delim, item);
    }, []);
}

function spreadArrayConcat(array, delim) {
    return array.reduce(function (result, item, i) {
        return result.concat(delim, item);
    }, []).slice(0, -1);
}

function spreadArrayComparison(array, delim) {
    return array.reduce(function (result, item, i) {
         if (i === 0) {
           result.push(item);
         } else {
           result.push(delim, item);
         }
      
        return result;
    }, []);
}

function spreadArrayPop(array, delim) {
    var r = array.reduce(function (result, item) {
        result.push(item, delim);      
        return result;
    }, []);
    r.pop();
    return r;
}

function spreadArrayShift(array, delim) {
    var r = array.reduce(function (result, item) {
        result.push(delim, item);      
        return result;
    }, []);
    r.shift();
    return r;
}

function spreadArraySlice(array, delim) {
    return array.reduce(function (result, item) {
        result.push(delim, item);      
        return result;
    }, []).slice(1);
}

function spreadArrayTailSlice(array, delim) {
    return array.reduce(function (result, item) {
        result.push(delim, item);
        
        return result;
    }, []).slice(0, -1);
}

function spreadArraySlice2(array, delim) {
    return array.slice(1).reduce(function (result, item) {
        result.push(delim, item);      
        return result;
    }, []);
}


function spreadArrayFor(arr, delim) {
    var result = [];
    for (var i = 0; i < arr.length; i++) {
    	result.push(arr[i], delim);
    };
    result.pop();
    return result;
}

function spreadArrayForReverse(arr, delim) {
    var result = []
    for (var i = arr.length - 1; i >= 0; i--) {
        result.unshift(arr[i], delim);
    };
    result.pop();
    return result;
}

function spreadArrayForComparison(arr, delim) {
    var result = [];
    for (var i = 0; i < arr.length; i++) {
      	if (i === 0) {
          result.push(arr[i]);
        } else {
          result.push(delim, arr[i]);
        }
    };
    return result;
}

function spreadArrayForWithInit(arr, delim) {
    var result = [arr[0]]
    for (var i = 1; i < arr.length; i++) {      	
        result.push(delim, arr[i]);
    };
    return result;
}

function spreadArrayForEach(arr, delim) {
    var result = [];
	arr.forEach(function(el, i){
      	if (i === 0) {
          result.push(el);
        } else {
          result.push(delim, el);
        }      
    });
    return result;
}

Tests:

ComparisonAndConcat
spreadArrayComparisonAndConcat(testArray, delim);
Concat
spreadArrayConcat(testArray, delim);
Comparison
spreadArrayComparison(testArray, delim);
Pop
spreadArrayPop(testArray, delim);
Shift
spreadArrayShift(testArray, delim);
Slice
spreadArraySlice(testArray, delim);
TailSlice
spreadArrayTailSlice(testArray, delim);
Slice2
spreadArraySlice2(testArray, delim);
For
spreadArrayFor(testArray, delim);
ForReverse
spreadArrayForReverse(testArray, delim);
ForComparison
spreadArrayForComparison(testArray, delim);
ForWithInit
spreadArrayForWithInit(testArray, delim);
ForEach
spreadArrayForEach(testArray, delim);

Run results for: spreadArray

Function that works like a join, but returns array

ComparisonAndConcat

Concat

Comparison

Pop

Shift

Slice

TailSlice

Slice2

For

ForReverse

ForComparison

ForWithInit

ForEach