<!doctype html> <html> <head> <meta charset="utf-8"> <title>js密码强度</title> <style type="text/css"> .pw_letter{ margin-top:5px; font-size: 12px; } .pw_letter label{float: left; margin-right:10px; cursor: default; font-size: 12px; line-height: 16px;;} .pw_letter span{ float: left; display:inline-block; width:30px; height:16px; line-height:16px; text-align:center;
color:#FFF; background-color:#ccc; border-left: 1px solid #FFF;} .pw_letter span.pw_strength_color{ background-color:green;} </style> </head> <body> <input id="password" type="password" name="password" placeholder="密码" onKeyUp="setPasswordStrength(this.value.trim())"> <div class="pw_letter"><label>安全程度</label> <span class="strength">弱</span> <span class="strength">中</span>
<span class="strength">强</span> </div> <script type="text/javascript"> /* *密码安全程度 *return 1 ：全部为字母或者数字,或者密码长度小于6 *return 2 : 字母数字组成，或者字母特殊字符，或者数字和特殊字符 *return 3 : 字母和数字和特殊字符 */ String.prototype.passwordStrength=function(){ if(this.length>0 && this.length<=6) return 1; var n1 = (this.search(/[a-zA-Z]/) != -1) ? 1 : 0, n2 = (this.search(/[0-9]/) != -1) ? 1 : 0, n3 =(this.search(/[\~\`\!\@\#\$\%\^\&\*\(\)\_\+\-\=\[\]|{\}\;\‘\:\"\,\.\/\<\>\?]{1,}/) != -1) ? 1 : 0; return n1+n2+n3; } String.prototype.trim = String.prototype.trim || function(){ return this.replace(/^\s+|\s+$/g,""); } function setPasswordStrength(pwd){ var strength_span = document.getElementsByClassName("strength"); for(var i=0; i<strength_span.length; i++){ strength_span.item(i).className="strength"; } for(var i=0; i<pwd.passwordStrength(); i++){ document.getElementsByClassName("strength").item(i).className="strength pw_strength_color"; } } </script> </body> </html>
原文：http://www.cnblogs.com/wuheng1991/p/5159407.html