javascipt小技巧之伪数组的转换

    var slice = window.dispatchEvent ? function(nodes, start, end) {        return [].slice.call(nodes, start, end);    } : function(nodes, start, end) {        var ret = [],n = nodes.length;        if (end === void 0 || typeof end === "number" && isFinite(end)) {start = parseInt(start, 10) || 0;//void 0的目的是获取纯正的undefined,undefined原则上可以被重写end = end == void 0 ? n : parseInt(end, 10);if (start < 0) {    start += n;}if (end > n) {    end = n;}if (end < 0) {    end += n;}for (var i = start; i < end; ++i) {    ret[i - start] = nodes[i];}        }        return ret;    };