时间:2021-07-01 10:21:17 帮助过:190人阅读
filter
被添加到 ECMA-262 标准第 5 版中,因此在某些实现环境中不被支持。可以把下面的代码插入到脚本的开头来解决此问题,该代码允许在那些没有原生支持 filter
的实现环境中使用它。
if (!Array.prototype.filter)
{
Array.prototype.filter = function(fun /*, thisArg */)
{
"use strict";
if (this === void 0 || this === null)
throw new TypeError();
var t = Object(this);
var len = t.length >>> 0;
if (typeof fun !== "function")
throw new TypeError();
var res = [];
var thisArg = arguments.length >= 2 ? arguments[1] : void 0;
for (var i = 0; i < len; i++)
{
if (i in t)
{
var val = t[i];
// NOTE: Technically this should Object.defineProperty at
// the next index, as push can be affected by
// properties on Object.prototype and Array.prototype.
// But that method's new, and collisions should be
// rare, so use the more-compatible alternative.
if (fun.call(thisArg, val, i, t))
res.push(val);
}
}
return res;
};
}