Question

我试图计算任何年龄的出生年份，但我不能这样做。我没有看到任何错误，计算功能正常，但它没有输出任何值。我认为错误在于计算功能..

＆＃13;

<!DOCTYPE html>
<html>

<head>
  <meta charset="utf-8">
  <title>BirthDate</title>
  <link rel="stylesheet" type="text/css" href="style.css">

</head>

<body style="background-color: #bfc5c5">
  <form style="margin-top:10px">
    <input type="number" name="number" style="height:30px;width: 400px;padding-left: 10px" placeholder="type your age" id="number">
    <input type="button" value="find year" id="button" style="height: 35px">
    <p id="year">year</p>
  </form>

  <script type="text/javascript">
    function calculate() {
      var number = document.getElementById("number").value;

      if (number == "" || number == 0) {
        window.alert("Please type your correct age!");
        return;
      }

      var date = new(Date()).getFullYear()
      var birthyear = number - date;

      document.getElementById("year").style.display = "block";
      document.getElementById("year").innerHTML = "Your Birth Year is " + birthyear;

    }

    document.getElementById("year").style.display = "none";
    document.getElementById("button").onclick = function {
      calculate();
    };
  </script>

</body>

</html>

＆＃13;

Answer 1

您要从括号中包含的Date构造函数中遗漏new：

var date = (new Date()).getFullYear();

错过了onClick事件处理程序的一组括号：

document.getElementById("button").onclick = function() {...}

Answer 2

您的代码中有两个错误，当您修复它们时，一切顺利：

功能错过了括号()：

 document.getElementById("button").onclick = function  {
 ____________________________________________________^^

应该是：

 document.getElementById("button").onclick = function() {

您的日期定义在：

中有额外的括号()

var date = new(Date()).getFullYear();
______________^______^

应该是：

var date = new Date().getFullYear();

希望这有帮助。

工作片段：

＆＃13;

function calculate() {
  var number = document.getElementById("number").value;

  if (number == "" || number == 0) {
    window.alert("Please type your correct age!");
    return;
  }

  var date = new Date().getFullYear()
  var birthyear = number - date;

  document.getElementById("year").style.display = "block";
  document.getElementById("year").innerHTML = "Your Birth Year is " + birthyear;
}


document.getElementById("year").style.display = "none";
document.getElementById("button").onclick = function() {
  calculate();
};

＆＃13;

body {
  background-color: #bfc5c5;
}

＆＃13;

<form style="margin-top:10px">
  <input type="number" name="number" style="height:30px;width: 400px;padding-left: 10px" placeholder="type your age" id="number">
  <input type="button" value="find year" id="button" style="height: 35px">
  <p id="year">year</p>
</form>

＆＃13;

用javascript计算出生年份

2 个答案:

工作片段：