​x
 
<!DOCTYPE html>
<html>
<body>
​
密码：<input type="password" id="myPsw" value="psw123456">
​
<p>单击该按钮可显示密码字段的默认值。</p>
​
<button type="button" onclick="myFunction()">试一试</button>
​
<p id="demo"></p>
​
<script>
function myFunction() {
  var x = document.getElementById("myPsw").defaultValue;
  document.getElementById("demo").innerHTML = x;
}
</script>
​
</body>
</html>
​