Password validation as per coding convention

//Declaration

-(BOOL) isPasswordValid:(NSString *)pwd; 

//Usage

int length=[passwordString length];        

if( length<8 || length >10 || (![self isPasswordValid:passwordString])) {

            

     NSString *alertMsg=@"Password length should be between 8 to 10 characters.Password must have at least 1 alphabet and 1 numeral(0-9)";

     

     [AlertView showAlert:alertMsg WithDelegate:self andTag:555];

     textField.text=@"";            

 }

//Method 

-(BOOL) isPasswordValid:(NSString *)pwd{

    

    NSRange rang;

    isValid=YES;

    rang = [pwd rangeOfCharacterFromSet:[NSCharacterSet letterCharacterSet]];

    if (!rang.length ){

        isValid=NO;// no letter        

    }    

    rang = [pwd rangeOfCharacterFromSet:[NSCharacterSet decimalDigitCharacterSet]];

    if (!rang.length) {

     isValid=NO;  // no numb

    }

    return isValid;

}