JS property read/write micro benchmark

setprop.js

function bench(x) {
    for (var i = 0; i < 10000000; i++) {
       x.foo = x.baz;
       x.bar = x.mur;
       x.dng = x.foo;
       x.baz = x.bar;
       x.mur = x.dng;
    }
}

if (typeof console === "undefined") console = {log: print};

var obj = {
    foo: "foo",
    bar: "bar",
    dng: "dng",
    baz: "baz",
    mur: "mur"
};

for (var k = 0; k < 10; k++) {
    var start = new Date().getTime();
    bench(obj);
    console.log(new Date().getTime() - start);
}

console.log(JSON.stringify(obj));