//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=0i<4i++){
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=0i<sPW.lengthi++){
//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=10 onKeyUp=pwStrength(this.value) onBlur=pwStrength(this.value)>
密码强度:
<table width="217" border="1" cellspacing="0" cellpadding="1" bordercolor="#cccccc" height="23" style='display:inline'>
<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>
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 。<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=0i<4i++){
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=0i<sPW.lengthi++){
//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 width="210" border="1" cellspacing="0" cellpadding="1" bordercolor="#eeeeee" height="22" style='display:inline'>
<tr align="center" bgcolor="#f5f5f5">
<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>
</body>
</html>
