For validity of a password, you need to recall the concept when your create a password to signup to a website.
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 upper case
One special char
One lower case
No white space
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;
One upper case
if (!passwd.Any(char.IsUpper)) return false;
Atleast one lower case
if (!passwd.Any(char.IsLower)) return false;
No white space
if (passwd.Contains(" "))
return false;Check for one special character
string specialCh = @"%!@#$%^&*()?/>.<,:;'\|}]{[_~`+=-" + "\"";
char[] specialCh = specialCh.ToCharArray();
foreach (char ch in specialChArray) {
if (passwd.Contains(ch))
return true;
}