nodejs的readline如何变成同步？还是采用一个异步循环?

就是设计成异步，你又要同步，不用它就同步了
你要想简单的说明下而不是学习node.js，建个html文件
写个javascript演示不就行了

var bFlag   =true;
var num     =0;
function init(){    
    while(bFlag){
        var ret = prompt("请输入内容！","");
        switch(ret){
        case "1":
            check(1,num++);
        break;
        case null:
        exitGuess(false);
        break;
        default:        
        break;
        }       
    }
}
function exitGuess(b){
    bFlag =b;
}
function check(code,num){
    //code means choose first
    //num  means the answer
    alert("This answer num is: "+num+"\r\nYou choose: "+code+" \r\nYou are smart.");
}