解决ie8不支持indexof()的方法

if (!Array.prototype.indexOf){ Array.prototype.indexOf = function(elt /*, from*/){ var len = this.length >>> 0; var from = Number(arguments[1]) || 0; from = (from < 0) ? Math.ceil(from) : Math.floor(from); if (from < 0) from += len; for (; from < len; from++) { if (from in this && this[from] === elt) return from; } return -1; }; }

把以上代码放到indexof方法的上边那即可