How to compare two arrays in node js?

Question

I am having two arrays, how can i compare the two arrays at single shot.

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

   if(arr1 == a         


        

Answer 1

The top answer is good, but I would also consider using Array.prototype:

Array.prototype.equals = function (arr) {
    return this.length == arr.length && this.every((u, i) => u === arr[i]);
}

console.log([1,2,3].equals([1,2,3])); // true
console.log([1,2,3].equals([1,3,3])); // false
// BUT!
console.log(["a",NaN,"b"].equals(["a",NaN,"b"])); // false, because NaN !== NaN

If you want it to work for NaNs too and distinguish +0 and -0, better use this:

Array.prototype.equals = function (arr) {
    function is(a, b) { // taken from the top answer
        return a === b && (a !== 0 || 1 / a === 1 / b) // false for +0 vs -0
            || a !== a && b !== b; // true for NaN vs NaN
    }
    return this.length == arr.length && this.every((u, i) => is(u, arr[i]));
}

console.log(["a",NaN,"b"].equals(["a",NaN,"b"])); // true