C# program to check password validity

While creating a password, you may have seen the validation requirements on a website like a password should be strong and have −

• Min 8 char and max 14 char
• One lower case
• No white space
• One upper case
• One special char

Let us see how to check the conditions one by one −

Min 8 char and max 14 char

if (passwd.Length < 8 || passwd.Length > 14)
return false;

Atleast one lower case

if (!passwd.Any(char.IsLower))
return false;

No white space

if (passwd.Contains(" "))
return false;

One upper case

if (!passwd.Any(char.IsUpper))
return false;

Check for one special character

string specialCh = @"%!@#$%^&*()?/>.<,:;'\|}]{[_~`+=-" + "\"";
char[] specialCh = specialCh.ToCharArray();
foreach (char ch in specialChArray) {
   if (passwd.Contains(ch))
      return true;
}