Use JavaScript implementation to evaluate the strength of user input password

JavaScript passwords are an essential tool in our lives, but an unsafe password can cause unnecessary damage. " As a web designer, if we can make a security assessment of the password entered by the user in the Web page and display the corresponding prompts, it will be helpful to set a secure password for the user. At the same time make the site more humane, more attractive.
What is a secure password? This procedure is evaluated in the following manner.
1. If the password is less than 5 digits, it is considered a weak password.
2. If the password is made up of only one of the numbers, lowercase letters, capitals, or other special symbols, it is considered a weak password.
3. If the password is composed of numbers, lowercase letters, capitals, or other special symbols, it is considered to be a moderate security password.
4. If the password consists of more than three of the numbers, lowercase letters, capitals, or other special symbols, it is considered a safe password.

The specific procedure is as follows (Demo address: Http://www.netInter.cn/reg):

<script language=javascript>

Program Design: Global worldwide, professional domain name registration, virtual hosting services
URL: http://www.netInter.cn
This procedure is the World Wide Web original procedure, if need to reprint, please indicate the website and source, thank you.
The above information and the text of the article is an inseparable part, so if you want to reprint this article, you must retain the above information.

Charmode function
Test what kind of character it belongs to.
function Charmode (in) {
if (in>=48 && in <=57)//number
return 1;
if (in>=65 && in <=90)//Uppercase
return 2;
if (in>=97 && in <=122)//lowercase
return 4;
Else
return 8; Special characters
}

Bittotal function
Calculates how many patterns there are in the current password
function Bittotal (num) {
modes=0;
for (i=0;i<4;i++) {
if (num & 1) modes++;
num>>>=1;
}
return modes;
}

Checkstrong function
Returns the strength level of a password

function Checkstrong (SPW) {
if (spw.length<=4)
return 0; Password is too short
modes=0;
for (i=0;i<spw.length;i++) {
Test the category of each character and count how many patterns there are.
Modes|=charmode (Spw.charcodeat (i));
}

Return Bittotal (Modes);

}

Pwstrength function
Displays different colors at different levels when the user releases the keyboard or password input box from losing focus

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= "" >
Enter Password: <input type=password size=10 onkeyup=pwstrength (this.value) onblur=pwstrength (this.value) >
<br> Password Strength:
<table width= "217" border= "1" cellspacing= "0" cellpadding= "1" bordercolor= "#cccccc" height= "" style= ' Display: Inline ' >
<TR align= "center" bgcolor= "#eeeeee" >

<TD width= "33%" id= "strength_l" > Weak </td>

<TD width= "33%" id= "Strength_m" > </td>

<TD width= "33%" id= "Strength_h" > Strong </td>
</tr>
</table>

</form>