有“回归假”;不在函数中的“if”语句的代码？

Question

我目前正在进行课堂作业，我们正在学习if / else语句。我想知道return false;语句是否存在与if类似的代码。

例如：

var why = prompt("Why won't you fill in my prompt?");

if(why === "" || why === null){
   // How can you make this false, so that it will ask the prompt question again?
   return false; /*Like that--but not a function*/
}

Answer 1

首先为响应定义一个容器，然后提示它，直到它是一个可接受的值：

var reason = null;

while (reason === "" || reason === null) {
  reason = prompt("Why won't you fill in my prompt?");
}

// continue with the reason defined

Answer 2

   var why=null; 

   while (why===null||why===""){
        why = prompt("Why won't you fill in my prompt?");
    }