How to compare two arrays in node js?

var arr1 = ["a","b","c"];
var arr2 = ["a","c","d"];

if (arr1.length == arr2.length
    && arr1.every(function(u, i) {
        return u === arr2[i];
    })
) {
   console.log(true);
} else {
   console.log(false);
}

---

Side note for edge cases:

=== is often considered slightly broken for this kind of task because NaN behaves unexpectedly:

var arr1 = ["a",NaN,"b"];
var arr2 = ["a",NaN,"b"];

if (arr1.length == arr2.length
    && arr1.every(function(u, i) {
        return u === arr2[i];
    })
) {
   console.log(true);
} else {
   console.log(false);
}

The code above actually logs false because NaN !== NaN. In addition, === can't distinguish +0 from -0. To cover both of these cases, you could use a stronger comparison known as "egal" or "is", which can easily be implemented like so:

function is(a, b) {
    return a === b && (a !== 0 || 1 / a === 1 / b) // false for +0 vs -0
        || a !== a && b !== b; // true for NaN vs NaN
}

var arr1 = ["a",NaN,"b"];
var arr2 = ["a",NaN,"b"];

if (arr1.length == arr2.length
    && arr1.every(function(u, i) {
        // Use "is" instead of "==="
        return is(u, arr2[i]);
    })
) {
   console.log(true);
} else {
   console.log(false);
}

[ES6]

Top answer is good & enough.

But when you just want to compare its values are same you have to sort it before. here's no need sort code.

if(arr1.length == arr2.length && arr1.every((v) => arr2.indexOf(v) >= 0)) {
    console.log(true);
} else {
    console.log(false);
}

And.. I think using a 'some' instead of 'every' is better.

If those are not same, 'some' gives you a early exit. - very little early but early ;)

if(arr1.length == arr2.length && !arr1.some((v) => arr2.indexOf(v) < 0)) {
    console.log(true);
} else {
    console.log(false);
}

I would make use of underscore for this.

var same = (_.difference(arr1, arr2).length == 0)