获取函数参数,测试性能

var str = "matrix(1, 0, 0, 1, -500, 0)";
var reg = /([^,]+),[^,]+\)$/g;

console.time("111");
console.log(reg.exec(str)[1]);
console.timeEnd("111");

/**
 * n=0  获取函数名
 * n>0  获取函数参数
 */
function findParam(str,n){
    var len = str.length;
    var count = 0;
    var ret = '';
    for(var i=0;i<len;i++){
        if(str[i]==','||str[i]==')'||str[i]=='('){
            if(++count==n+1) return ret;
        }else if(count==n){
            ret += str[i];
        }
    }
    return ret;
}

console.time("222");
console.log(findParam(str,5));
console.timeEnd("222");