js判斷密碼強度

html代碼：

 1 <form name="form1" action="">
 2     密碼:<input type="password" size="8" onkeyup="pwStrength(this.value)" onblur="pwStrength(this.value)">
 3     <br>
 4     密碼強度:
 5     <table width="220px" border="1" cellspacing="0" cellpadding="1" bordercolor="#eeeeee" height="22px">
 6         <tr align="center" bgcolor="#f5f5f5">
 7             <td width="33%" id="strength_L">弱</td>
 8             <td width="33%" id="strength_M">中</td>
 9             <td width="33%" id="strength_H">強</td>
10         </tr>
11     </table>
12 </form>

 

js代碼：

 1 function pwdStrength(pwd) {
 2     O_color = "#eeeeee";
 3     L_color = "#FF0000";
 4     M_color = "#FF9900";
 5     H_color = "#33CC00";
 6     var level = 0, strength = "O";
 7     if (pwd == null || pwd == '') {
 8         strength = "O";
 9         Lcolor = Mcolor = Hcolor = O_color;
10     }
11     else {
12         var mode = 0;
13         if (pwd.length <= 4)
14             mode = 0;
15         else {
16             for (i = 0; i < pwd.length; i++) {
17                 var charMode, charCode;
18                 charCode = pwd.charCodeAt(i);
19                 // 判斷輸入密碼的類型
20                 if (charCode >= 48 && charCode <= 57) //數字  
21                     charMode = 1;
22                 else if (charCode >= 65 && charCode <= 90) //大寫  
23                     charMode = 2;
24                 else if (charCode >= 97 && charCode <= 122) //小寫  
25                     charMode = 4;
26                 else
27                     charMode = 8;
28                 mode |= charMode;
29             }
30             // 計算密碼模式
31             level = 0;
32             for (i = 0; i < 4; i++) {
33                 if (mode & 1)
34                     level++;
35                 mode >>>= 1;
36             }
37         }
38         switch (level) {
39             case 0:
40                 strength = "O";
41                 Lcolor = Mcolor = Hcolor = O_color;
42                 break;
43             case 1:
44                 strength = "L";
45                 Lcolor = L_color;
46                 Mcolor = Hcolor = O_color;
47                 break;
48             case 2:
49                 strength = "M";
50                 Lcolor = Mcolor = M_color;
51                 Hcolor = O_color;
52                 break;
53             default:
54                 strength = "H";
55                 Lcolor = Mcolor = Hcolor = H_color;
56                 break;
57         }
58     }
59     document.getElementById("strength_L").style.background = Lcolor;
60     document.getElementById("strength_M").style.background = Mcolor;
61     document.getElementById("strength_H").style.background = Hcolor;
62     return strength;
63 }