ArrayLike/Array shallow copy bench mark

array.bench.md

bench result

• Chrome 30 で A = B*3
• Firefox 22 で A = B

function A(obj, i) {
    var rv = Array.apply(null, obj);
    rv.push(i);
}

function B(obj, i) {
    var rv = Array.prototype.slice.call(obj);
    rv.push(i);
}


function test1() {
    var now = Date.now();
    var array1 = [];
    for (var i = 0; i < 10000; ++i) {
        array1.push(i);
        A(array1);
    }
    console.log("tick1: " + (Date.now() - now));
}


function test2() {
    var now = Date.now();
    var array2 = [];
    for (var i = 0; i < 10000; ++i) {
        array2.push(i);
        B(array2);
    }
    console.log("tick2: " + (Date.now() - now));
}

Date.now() % 2 ? (test1(), test2()) : (test2(), test1());