Polyfill for Array.indexOf(searchElement, fromIndex)

Array.indexOf.polyfill.js

if (!Array.prototype.indexOf) {
  Array.prototype.indexOf = function (searchElement, fromIndex) {
    var k;
    if (this == null) {
      throw new TypeError('"this" is null or not defined');
    }
    var O = Object(this);
    var len = O.length >>> 0;
    if (len === 0) {
      return -1;
    }
    var n = +fromIndex || 0;
    if (Math.abs(n) === Infinity) {
      n = 0;
    }
    if (n >= len) {
      return -1;
    }
    k = Math.max(n >= 0 ? n : len - Math.abs(n), 0);
    while (k < len) {
      var kValue;
      if (k in O && O[k] === searchElement) {
        return k;
      }
      k++;
    }
    return -1;
  };
}