html运行实例（js_comparison_26）-搜寻教程库

代码示例：（标识：js_comparison_26）

<!DOCTYPE html>
<html>
<body>

<h1>JavaScript 比较</h1>

<p>请输入您的年龄然后点击按钮：</p>

<input id="age" value="18" />

<button onclick="myFunction()">试一试</button>

<p id="demo"></p>

<script>
function myFunction() {
  var age, voteable;
  age = Number(document.getElementById("age").value);
  if (isNaN(age)) {
    voteable = "输入值不是数字";
  } else {
    voteable = (age < 18) ? "好年轻" : "够成熟";
  }
  document.getElementById("demo").innerHTML = voteable;
}
</script>

</body>
</html>