js怎么实现密码的强弱?

我看到很多网站都会根据你输入的密码来判断强弱..
我昨天用onchange事件试了一下结果不行.
有谁知道怎么做的？

解决方案 »

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//密码强度;
function PasswordStrength(showed){
this.showed = (typeof(showed) == "boolean")?showed:true;
this.styles = new Array();
this.styles[0] = {backgroundColor:"#EBEBEB",borderLeft:"solid 1px #FFFFFF",borderRight:"solid 1px #BEBEBE",borderBottom:"solid 1px #BEBEBE"};
this.styles[1] = {backgroundColor:"#FF4545",borderLeft:"solid 1px #FFFFFF",borderRight:"solid 1px #BB2B2B",borderBottom:"solid 1px #BB2B2B"};
this.styles[2] = {backgroundColor:"#FFD35E",borderLeft:"solid 1px #FFFFFF",borderRight:"solid 1px #E9AE10",borderBottom:"solid 1px #E9AE10"};
this.styles[3] = {backgroundColor:"#95EB81",borderLeft:"solid 1px #FFFFFF",borderRight:"solid 1px #3BBC1B",borderBottom:"solid 1px #3BBC1B"};

this.labels= ["弱","中","强"]; this.divName = "pwd_div_"+Math.ceil(Math.random()*100000);
this.minLen = 5;

this.width = "300px";
this.height = "16px";

this.content = "";

this.selectedIndex = 0;

this.init();
}
PasswordStrength.prototype.init = function(){

var s = '<table cellpadding="0" id="'+this.divName+'_table" cellspacing="0" style="width:'+this.width+';height:'+this.height+';">';
s += '<tr>';
for(var i=0;i<3;i++){
s += '<td id="'+this.divName+'_td_'+i+'" width="33%" align="center"><span style="font-size:1px"> </span><span id="'+this.divName+'_label_'+i+'" style="display:none;font-family: Courier New, Courier, mono;font-size: 12px;color: #000000;">'+this.labels[i]+'</span></td>';
}
s += '</tr>';
s += '</table>';
this.content = s;
if(this.showed){
document.write(s);
this.copyToStyle(this.selectedIndex);
}
}
PasswordStrength.prototype.copyToObject = function(o1,o2){
for(var i in o1){
o2[i] = o1[i];
}
}
PasswordStrength.prototype.copyToStyle = function(id){
this.selectedIndex = id;
for(var i=0;i<3;i++){
if(i == id-1){
this.$(this.divName+"_label_"+i).style.display = "inline";
}else{
this.$(this.divName+"_label_"+i).style.display = "none";
}
}
for(var i=0;i<id;i++){
this.copyToObject(this.styles[id],this.$(this.divName+"_td_"+i).style);
}
for(;i<3;i++){
this.copyToObject(this.styles[0],this.$(this.divName+"_td_"+i).style);
}
}
PasswordStrength.prototype.$ = function(s){
return document.getElementById(s);
}
PasswordStrength.prototype.setSize = function(w,h){
    document.getElementById(this.divName+"_table").style.width = w;
    document.getElementById(this.divName+"_table").style.height = h;
//this.width = w;
//this.height = h;
}
PasswordStrength.prototype.setMinLength = function(n){
if(isNaN(n)){
return ;
}
n = Number(n);
if(n>1){
this.minLength = n;
}
}
PasswordStrength.prototype.setStyles = function(){
if(arguments.length == 0){
return ;
}
for(var i=0;i<arguments.length && i < 4;i++){
this.styles[i] = arguments[i];
}
this.copyToStyle(this.selectedIndex);
}
PasswordStrength.prototype.write = function(s){
if(this.showed){
return ;
}
var n = (s == 'string') ? this.$(s) : s;
if(typeof(n) != "object"){
return ;
}
n.innerHTML = this.content;
this.copyToStyle(this.selectedIndex);
}
PasswordStrength.prototype.update = function(s){
if(s.length < this.minLen){
this.copyToStyle(0);
return;
}
var ls = -1;
if (s.match(/[a-z]/ig)){
ls++;
}
if (s.match(/[0-9]/ig)){
ls++;
}
if (s.match(/(.[^a-z0-9])/ig)){
ls++;
}
if (s.length < 6 && ls > 0){
ls--;
}
switch(ls) {
case 0:
this.copyToStyle(1);
break;
case 1:
this.copyToStyle(2);
break;
case 2:
this.copyToStyle(3);
break;
default:
this.copyToStyle(0);
}
}
//onkeyup中调用
<input id="pwd" runat="server" onkeyup="ps.update(this.value);" type="password"/>具体的，楼主自己研究
呵呵，刚把以前项目用的分离出来
<html>
<head>
<script type="text/javascript">
function checkstr(str)
{

if(str>=48&&str<=57)//数字
{
  return 1;
}
else if(str>=65&&str<=90)//大写字母
{
  return 2;
}
else if(str>=97&&str<=122)//小写字母
{
  return 3;
}
else//特殊字符
{
  return 4;
}
}
function checkl(string)
{
n=false;
s=false;
t=false;
l_num=0;
if(string.length<6)
{
  l_num=1;
}
else
{
  for(i=0;i<string.length;i++)
  {
   asc=checkstr(string.charCodeAt(i));
   if(asc==1&&n==false){l_num+=1;n=true;}
   if((asc==2||asc==3)&&s==false){l_num+=1;s=true;}
   if(asc==4&&t==false){l_num+=1;t=true;}
  }
}
return l_num;
}function checklevel(psw)
{
if(psw!=""){
document.getElementById("pwdisok").style.display="block";
}else{
document.getElementById("pwdisok").style.display="none";
}
color="#ededed";
color_l="#ff0000";
color_m="#ff9900";
color_h="#33cc00";
if(psw==null||psw=='')
{
  lcor=color;
  mcor=color;
  hcor=color;
}
else
{
thelev=checkl(psw)
switch(thelev)
  {
   case 1:
   lcor=color_l;
   hcor=mcor=color;
   break;
   case 2:
   mcor=lcor=color_m;
   hcor=color;
   break;
   case 3:
   hcor=mcor=lcor=color_h;
   break;
   default:
   lcor=mcor=hcor=color;
  }
}
document.getElementById("pwd_small").style.background=lcor;
document.getElementById("pwd_center").style.background=mcor;
document.getElementById("pwd_ok").style.background=hcor;
}
  function checksubmit(){
   if(document.getElementById("pwd_small").style.background=="#ff0000"){
alert("你的密码强度太弱,建议你用字母、数字、下划线、特殊字符组合密码!");
   }
}
</script>
</head>
<body>
<div id="qqpwd">
设置密码 :  
<input type="password"
onKeyUp="checklevel(this.value)" onBlur="checklevel(this.value)">
</div> <div id="pwdisok" style="display: none;width:330px;">

<span id="pwd_small" style="width:100px;text-align:center;">弱</span>
<span id="pwd_center" style="width:100px;text-align:center;">中</span>
<span id="pwd_ok" style="width:100px;text-align:center;">强</span>
</div>
         <br>
<input type="button" value="提交" onclick="checksubmit()" />
</body>
试试这个<script language=javascript>
//CharMode函数
//测试某个字符是属于哪一类
function CharMode(iN) {
   if (iN>=48 && iN <=57) //数字
    return 1;
   if (iN>=65 && iN <=90) //大写字母
    return 2;
   if (iN>=97 && iN <=122) //小写
    return 4;
   else
    return 8; //特殊字符
}//bitTotal函数
//计算出当前密码当中一共有多少种模式
function bitTotal(num) {
   modes=0;
   for (i=0;i<4;i++) {
    if (num & 1) modes++;
     num>>>=1;
    }
   return modes;
}//checkStrong函数
//返回密码的强度级别
function checkStrong(sPW) {
   if (sPW.length<=4)
    return 0; //密码太短
    Modes=0;
    for (i=0;i<sPW.length;i++) {
     //测试每一个字符的类别并统计一共有多少种模式
     Modes|=CharMode(sPW.charCodeAt(i));
   }
   return bitTotal(Modes);
}//pwStrength函数
//当用户放开键盘或密码输入框失去焦点时,根据不同的级别显示不同的颜色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>  <form name="form1" action="">
输入密码:<input type="password" size="20" onKeyUp="pwStrength(this.value)" onBlur="pwStrength(this.value)" />
<br>密码强度:
<table width="200px" height="25" border="0" cellspacing="0" cellpadding="1" bordercolor="#cccccc" style='font-size:12px'>
<tr align="center" bgcolor="#eeeeee">
   <td width="33%" id="strength_L">弱</td>
   <td width="33%" id="strength_M">中</td>
   <td width="33%" id="strength_H">强</td>
</tr>
</table>
</form>
ls的思路都不错，可以利用正则判断密码强度
css+js控制显示强度系数即可
http://topic.csdn.net/u/20070424/13/6bdee50a-cad6-455b-a6ec-653d025baa43.html
翻老帖，当年其中10楼的回复曾经让俺佩服不已，只用1条正则就把密码分了4个等级。