compare values of array in javascript code example

Example 1: javascript compare arrays

Array.prototype.equals = function(arr2) {
  return (
    this.length === arr2.length &&
    this.every((value, index) => value === arr2[index])
  );
};

[1, 2, 3].equals([1, 2, 3]);	// true
[1, 2, 3].equals([3, 6, 4, 2]);	// false

Example 2: how to compare elements in an array

for (let i = 0; i < a.length; i++) {
    for (let k = i + 1; k < a.length; k++) {
        if (a[i] != a[k]) {
            //do stuff
        }
    }
}