javascript - 卡在 else if 循环中

Question

我正在为类做练习，我们正在创建待办事项列表。

我的问题是，当我输入我的 Todo 并按回车键时，我收到消息 Enter new Todo，而不是 Added todo。

看来我陷入了这个 else if 循环，它不会转到下一个 else if 语句。

var todos = ["Buy New Turtle"];

window.setTimeout(function() {

  var input = prompt("What would you like to do?");

  while(input !== "quit") {

    if(input === "list") {
      console.log("**********");
      todos.forEach(function(todo, i) {
        console.log(i + ": " + todo);
      })
      console.log("**********")
    }
    else if(input === "new") {
      var newTodo = prompt("Enter new todo");
      todos.push(newTodo);
      console.log("Added todo");
      }

    else if(input === "delete"){
      var index = prompt("Enter index of todo to delete");
      todos.splice(index, 1);
      }
  }
    input = prompt("What would you like to do?");

  console.log("OK, YOU QUIT THE APP");
}, 500);

Answer 1

您需要将 input 的重新声明放在 while 循环中。还要检查 input 是否真实 - 这样如果有人关闭提示框它就不会崩溃。

var todos = ["Buy New Turtle"];

window.setTimeout(function() {

  var input = prompt("What would you like to do?");

  while (input !== "quit" && input) {

    if (input === "list") {
      console.log("**********");
      todos.forEach(function(todo, i) {
        console.log(i + ": " + todo);
      })
      console.log("**********")
    } else if (input === "new") {
      var newTodo = prompt("Enter new todo");
      todos.push(newTodo);
      console.log("Added todo");
    } else if (input === "delete") {
      var index = prompt("Enter index of todo to delete");
      todos.splice(index, 1);
    }

    input = prompt("What would you like to do?");
  }

  console.log("OK, YOU QUIT THE APP");
}, 500);