javascript - 将用户输入的答案转换为小写并写入屏幕

Question

没有任何内容被写入屏幕。

控制台错误显示如下:

ReferenceError: ans is not defined**

代码如下:

预期结果应该是将提示中的用户输入处理为小写并写入页面。

任何帮助都会被考虑。谢谢

function lowerCase(ans) {
  var lowCase = ans.toLowerCase();
  return lowerCase;
}

var questions = ['How may strings does a violin have?', 'How many sides does an octagon have?',
  'How many NBA championships did Michael Jordan win with the Chicago Bulls?'
];

var answers = ['FOUR', 'EIGHT', 'SIX'];

var score = 0;

function quiz(counter) {
  var guesses = 3;

  while (guesses > 0) {
    var ans = prompt(questions[counter]);
    if (ans == answers[counter]) {
      alert("Correct!");
      return guesses;
    } else {
      guesses--;
      alert("Incorrect, You have " + guesses + " guesses remaining");
    }
  }
  return 0;
}

document.write(lowerCase(ans));

Answer 1

在函数中，不要使用 return lowerCase; 而是 return lowCase;。您将再次返回该函数，而不是必须返回包含小写文本的变量。在全局范围内定义 ans，而不是在 while 循环内。您还必须调用测验功能。 document.write 应该位于测验函数内部而不是外部

function lowerCase(ans) {
  var lowCase = ans.toLowerCase();
  return lowCase;
}

var ans='';

var questions = ['How may strings does a violin have?', 'How many sides does an octagon have?',
  'How many NBA championships did Michael Jordan win with the Chicago Bulls?'
];
var answers = ['FOUR', 'EIGHT', 'SIX'];

var score = 0;

function quiz(counter) {
  var guesses = 3;



  while (guesses > 0) {
     ans = prompt(questions[counter]);
    if (ans == answers[counter]) {
      alert("Correct!");
      return guesses;
    } else {
      guesses--;
      alert("Incorrect, You have " + guesses + " guesses remaining");
    }
  }
  document.write(lowerCase(ans));
}

quiz(2)