JS 密码强度校验的正则表达式(简单且好用)

最近一直在做通行证项目，里面的注册模块中输入密码需要显示密码强度（低中高）。今天就把做的效果给大家分享下，代码没有网上搜索的那么复杂，能够满足一般的需求。

html 代码如下：

				?

									<!DOCTYPE HTML>

									<html lang="en">

									<head>

									  <meta charset="utf-8"/>

									  <title>密码强度</title>

									  <style type="text/css">

									  #passStrength{height:6px;width:120px;border:1px solid #ccc;padding:2px;}

									  .strengthLv1{background:red;height:6px;width:40px;}

									  .strengthLv2{background:orange;height:6px;width:80px;}

									  .strengthLv3{background:green;height:6px;width:120px;}

									  </style>

									</head>

									<body>

									  <input type="password" name="pass" id="pass" maxlength="16"/>

									  <div class="pass-wrap">

									    <em>密码强度：</em>

									    <div id="passStrength"></div>

									  </div>

									</body>

									</html>

									<script type="text/javascript" src="js/passwordStrength.js"></script>

									<script type="text/javascript">

									new PasswordStrength('pass','passStrength');

									</script>

js 代码如下：

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									function PasswordStrength(passwordID,strengthID){

									  this.init(strengthID);

									  var _this = this;

									  document.getElementById(passwordID).onkeyup = function(){

									    _this.checkStrength(this.value);

									  }

									};

									PasswordStrength.prototype.init = function(strengthID){

									  var id = document.getElementById(strengthID);

									  var div = document.createElement('div');

									  var strong = document.createElement('strong');

									  this.oStrength = id.appendChild(div);

									  this.oStrengthTxt = id.parentNode.appendChild(strong);

									};

									PasswordStrength.prototype.checkStrength = function (val){

									  var aLvTxt = ['','低','中','高'];

									  var lv = 0;

									  if(val.match(/[a-z]/g)){lv++;}

									  if(val.match(/[0-9]/g)){lv++;}

									  if(val.match(/(.[^a-z0-9])/g)){lv++;}

									  if(val.length < 6){lv=0;}

									  if(lv > 3){lv=3;}

									  this.oStrength.className = 'strengthLv' + lv;

									  this.oStrengthTxt.innerHTML = aLvTxt[lv];

									};