JavaScript实现密码强度实时验证：原理与代码详解

完整代码实现

<div id = 'div1'>
 <input type="text" id = 'password' placeholder="密码"/>
 <div id = 'intension'>
 <div>弱</div>
 <div>中</div>
 <div>强</div>
 </div>
</div>

<style>
 #div1{width: 350px; height: 200px; background-color: orange; border: 1px solid black; margin: 100px auto; text-align: center; padding-top: 50px}
 #intension div{background-color: gray; width: 80px; height: 20px; text-align: center; line-height: 20px; margin: 5px; float: left; }
 #intension{width: 270px; margin-left: 40px}
 #password{width: 300px; height: 30px; font-size: 18px;}
 #intension .active{background-color: pink}
</style>

var oPassword = document.getElementById("password");
var oDiv = document.getElementById("intension");
var nodes = oDiv.getElementsByTagName("div");

oPassword.onkeyup = function(){
var oValue = oPassword.value;

  for(var i = 0; i < nodes.length; i++){
  nodes[i].className = '';
  } 

  if(/\d/.test(oValue) && /[a-z]/.test(oValue) && /[A-Z]/.test(oValue)){
  nodes[2].className = "active";
  }else if(/^\d+$/.test(oValue) || /^[A-Z]+$/.test(oValue) || /^[a-z]+$/.test(oValue)){
  nodes[0].className = "active";
  }else{
  nodes[1].className = "active";
  }

 }