Here you can find the source of lastIndexOf(e)
Array.prototype.lastIndexOf = function (e) { for (var i = this.length - 1, j; j = this[i]; i--) { if (j == e) { return i; } }//from ww w . jav a 2 s . c o m return -1; }
Array.prototype.lastIndexOf = function lastIndexOf(searchElement) { if (!(this instanceof Object)) { throw new TypeError(this + 'is not an object'); var array = this, arrayIsString = array instanceof String, length = array.length, index = 1 in arguments ? Number(arguments[1]) || 0 : length - 1; ...
Array.prototype.lastIndexOf = function(elem, from) { if (from == null) { from = this.length - 1; } else if (from < 0) { from = Math.max(0, this.length + from); for (var i = from; i >= 0; i--) { if (this[i] === elem) { return i; ...
Array.prototype.lastIndexOf = Array.prototype.lastIndexOf || function(elt ) { var len = this.length; var from = Number(arguments[1]); if (isNaN(from)) { from = len - 1; } else { from = (from < 0) ? Math.ceil(from) : Math.floor(from); ...
Array.prototype.lastIndexOf = function(item){ var lastIndex = -1; for (var i=0; i<this.length; i++){ if (this[i] === item){ lastIndex = i; return lastIndex;
Array.prototype.lastIndexOf = function (o) { var index = this.length; for (; index >= 0; index--) { if (index in this && this[index] === o) return index; return -1; };