复制代码 代码如下:

function StringResource(k) { return StringResource[k] || k; }

function RandomSelector() {

var f = 0, c = [];

return function (v, r) {

if (arguments.length) {

if (r <= 0) throw { message: StringResource("INVALID_ARGUMENT") };

c.push([r, v]);

f += r;

} else {

var i = 0; r = Math.random() * f;

for (; ; ) if ((r -= (v = c[i++])[0]) < 0) return v[1];

}

};

}