JSFiddle - React, Tailwind, and code Playground

by Khalil Zhang

JavaScript

var forEach = Array.prototype.forEach;

Array.prototype.unique = function () {
    var seen = [];
    var result = [];

    forEach.call(this, function (value, index) {
        if (seen.indexOf(value) == -1) {
            seen.push(value);
            result.push(value);
        }
    });
    return result;
}
var arr = [1, 2, 2, 3, 1];
console.log('before unique: ' + arr);
forEach.call(arr.unique(), function (v) {
    console.log(v);
});