javascript - 如何从第一个功能转到下一个功能？

Question

我一直通过阅读书籍和练习所学知识来自学和练习 JavaScript。我对如何让某些东西发挥作用有点困惑，希望你们能提供帮助。

        function guessAge(){
            var userInput = parseInt(prompt("Guess my age!", 100),10);

            if(userInput == 25){
                alert("Correct!");
            }else{
                alert("Incorrect");
            }

            return guessAge();
        }

        function guessMovie(){
            var input = prompt("Guess my favourite movie!");

            if(input == "Lego"){
                alert("Everything is awesome!");
            }else{
                alert("Incorrect!");
            }
        }

        guessAge(); //Initialise guessAge function
        guessMovie(); //Initialise guessMovie function

如果答案错误，我想让第一个函数重复，但如果答案正确，则继续执行下一个函数，但无论正确还是错误，return 似乎都会重复。

Answer 1

Rubber duck debugging是发现逻辑错误的好方法。注释中的内容是您在逐行执行代码时对橡皮鸭大声说的话。

function guessAge() {
  /*
    I'm asking the user for input with a default value of 100
    I'm then parsing a string to an integer that is base 10
    I store the result in userInput
  */
  var userInput = parseInt(prompt("Guess my age!", 100), 10);
  /*I check if the user input is 25 */
  if (userInput == 25) {
  /* The user input is 25 so I alert that they are correct */
    alert("Correct!");
  } else {
  /* otherwise I alert that they are incorrect */
    alert("Incorrect");
  }

  /*I return what guessAge returns. Right now there is no other 
    return statements out of the function so I will always call
    this line */
  return guessAge();
}

第一次通过后再次进行，但这次说出你想做什么。

function guessAge() {
  /*
    I want the user input to see if they can guess my age
  */
  var userInput = parseInt(prompt("Guess my age!", 100), 10);
  /*I check if the user input is 25 */
  if (userInput == 25) {
  /* The user input is 25 so I alert that they are correct */
    alert("Correct!");
  /* I want to leave the function guessAge after the user guesses
     correctly. */
  } else {
  /* otherwise I alert that they are incorrect */
    alert("Incorrect");
  /* I want to call guessAge again since the user guessed wrong */
  }

  /* this statement is out of my control flow block so it will always
     be reached, even if the user entered the correct age. I want to 
     leave the function when the user enters the correct answer but
     this line will allways call guessAge */
  return guessAge();
}

从那里您可以尝试一些解决方案。请记住，解决问题的方法有多种。

function guessAge() {
  var userInput = parseInt(prompt("Guess my age!", 100), 10);
  if (userInput == 25) {
    alert("Correct!");
  /* I want to leave the function guessAge after the user guesses
     correctly. if I do nothing after my else we will leave the 
     function without having to do anything */
  } else {
    alert("Incorrect");
  /* I want to call guessAge again since the user guessed wrong */
    guessAge();
  }
} 

请注意，您不必从函数返回任何内容。调用函数时也不必总是返回。当您想要将值返回给函数调用者时，可以使用 return。