http://toster.ru/q/51772

egor_nullptr.js

var arr = [];
for (var i = 0, l = 100*1000; i < l; i++) {
    arr.push(Math.round(Math.random() * l))
}

Array.prototype.diff = function(a) {
    return this.filter(function(i) {return !(a.indexOf(i) > -1);});
};

for (var i = 0; i < 10; ++i) {
    console.log(arr.diff(arr).length == 0);
}

ramntry.js

var arr = [];
for (var i = 0, l = 100*1000; i < l; i++) {
    arr.push(Math.round(Math.random() * l))
}

Array.prototype.hasAll = function(a) {
    var hash = this.reduce(function(acc, i) { acc[i] = true; return acc; }, {});
    return a.every(function(i) { return i in hash; });
};

for (var i = 0; i < 10; ++i) {
    console.log(arr.hasAll(arr));
}

ramntry@ramntry-R418:~/studies/javascript/hasAll$ time nodejs ramntry.js
true
true
true
true
true
true
true
true
true
true

real 0m0.528s
user 0m0.504s
sys  0m0.028s
ramntry@ramntry-R418:~/studies/javascript/hasAll$ time nodejs egor_nullptr.js 
true
true
true
true
true
true
true
true
true
true

real 1m47.103s
user 1m47.951s
sys  0m0.600s
ramntry@ramntry-R418:~/studies/javascript/hasAll$ nodejs --version
v0.10.22
ramntry@ramntry-R418:~/studies/javascript/hasAll$ cat /proc/cpuinfo
processor   : 0
-//-
model name  : Intel(R) Pentium(R) Dual  CPU  T3400  @ 2.16GHz
-//-
cache size  : 1024 KB