这段JavaScript代码比较实用，它完成用户注册时判断用户输入密码的强度，分强、弱、中三等级，它可以根据用户输入的密码显示对应的密码强弱等级，方便用户改进输入。
实现代码：
<html> <head> <title>JS判断密码强度</title> <script language=javascript> //判断输入密码的类型 function CharMode(iN){ if (iN>=48 && iN <=57) //数字 return 1; if (iN>=65 && iN <=90) //大写 return 2; if (iN>=97 && iN <=122) //小写 return 4; else return 8; } //bitTotal函数 //计算密码模式 function bitTotal(num){ modes=0; for (i=0;i<4;i++){ if (num & 1) modes++; num>>>=1; } return modes; } //返回强度级别 function checkStrong(sPW){ if (sPW.length<=4) return 0; //密码太短 Modes=0; for (i=0;i<sPW.length;i++){ //密码模式 Modes|=CharMode(sPW.charCodeAt(i)); } return bitTotal(Modes); } //显示颜色 function pwStrength(pwd){ O_color="#eeeeee"; L_color="#FF0000"; M_color="#FF9900"; H_color="#33CC00"; if (pwd==null||pwd==''){ Lcolor=Mcolor=Hcolor=O_color; } else{ S_level=checkStrong(pwd); switch(S_level) { case 0: Lcolor=Mcolor=Hcolor=O_color; case 1: Lcolor=L_color; Mcolor=Hcolor=O_color; break; case 2: Lcolor=Mcolor=M_color; Hcolor=O_color; break; default: Lcolor=Mcolor=Hcolor=H_color; } } document.getElementById("strength_L").style.background=Lcolor; document.getElementById("strength_M").style.background=Mcolor; document.getElementById("strength_H").style.background=Hcolor; return; } </script> </head> <body> <form name=form1 action="" > 密码:<input type=password size=8 onKeyUp=pwStrength(this.value) onBlur=pwStrength(this.value)> <br>密码强度: <table cellspacing="0" cellpadding="1" bordercolor="#eeeeee"> <tr bgcolor="#f5f5f5"> <td>弱</td> <td>中</td> <td>强</td> </tr> </table> </form> </body> </html>
这一款先看一看效果图。
具体内容：
<script> function AuthPasswd(string) { if(string.length >=6) { if(/[a-zA-Z]+/.test(string) && /[0-9]+/.test(string) && /\W+\D+/.test(string)) { noticeAssign(1); }else if(/[a-zA-Z]+/.test(string) || /[0-9]+/.test(string) || /\W+\D+/.test(string)) { if(/[a-zA-Z]+/.test(string) && /[0-9]+/.test(string)) { noticeAssign(-1); }else if(/\[a-zA-Z]+/.test(string) && /\W+\D+/.test(string)) { noticeAssign(-1); }else if(/[0-9]+/.test(string) && /\W+\D+/.test(string)) { noticeAssign(-1); }else{ noticeAssign(0); } } }else{ noticeAssign(null); } } function noticeAssign(num) { if(num == 1) { $('#weak').css({backgroundColor:'#009900'}); $('#middle').css({backgroundColor:'#009900'}); $('#strength').css({backgroundColor:'#009900'}); $('#strength').html('很强'); $('#middle').html(''); $('#weak').html(''); }else if(num == -1){ $('#weak').css({backgroundColor:'#ffcc33'}); $('#middle').css({backgroundColor:'#ffcc33'}); $('#strength').css({backgroundColor:''}); $('#weak').html(''); $('#middle').html('中'); $('#strength').html(''); }else if(num ==0) { $('#weak').css({backgroundColor:'#dd0000'}); $('#middle').css({backgroundColor:''}); $('#strength').css({backgroundColor:''}); $('#weak').html('弱'); $('#middle').html(''); $('#strength').html(''); }else{ $('#weak').html(' '); $('#middle').html(' '); $('#strength').html(' '); $('#weak').css({backgroundColor:''}); $('#middle').css({backgroundColor:''}); $('#strength').css({backgroundColor:''}); } } </script>