Email address validation in iOS

Background :~

Unlike other technologies, in iOS sometimes we need to verify email address entered by user, especially in registration & login screen. Following function will check the entered email address is valid or not and return the value based on validation.

Implementation :~

Utility.h

#import <Foundation/Foundation.h>

@interface Utility : NSObject

+(BOOL)isValidEmailAddress:(NSString *)emailAddress ;

+(BOOL) validateEmail:(NSString*) emailAddress ;

@end

Utility.m

#import "Utility.h"

@implementation Utility

// Using NSPredicate

+(BOOL)isValidEmailAddress:(NSString *)emailAddress {

   //Create a regex string

   NSString *stricterFilterString = @"[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,4}" ;

   //Create predicate with format matching your regex string

   NSPredicate *emailTest = [NSPredicate predicateWithFormat:

                             @"SELF MATCHES %@", stricterFilterString];

   //return true if email address is valid

   return [emailTest evaluateWithObject:emailAddress];

}

// Using NSRegularExpression

+(BOOL) validateEmail:(NSString*) emailAddress {

   

   NSString *regExPattern = @"^[A-Z0-9._%+-]+@[A-Z0-9.-]+\\.[A-Z]{2,4}$";

   NSRegularExpression *regEx = [[NSRegularExpression alloc]

                                 initWithPattern:regExPattern

                                 options:NSRegularExpressionCaseInsensitive

                                 error:nil];

   NSUInteger regExMatches = [regEx numberOfMatchesInString:emailAddress

                                                    options:0

                                                      range:NSMakeRange(0, [emailAddress length])];

   return (regExMatches == 0) ? NO : YES ;

}

How to Use :~

Validate email address by calling any of the above method. For example,

[Utility isValidEmailAddress:@"milan@example.com"]; OR

[Utility validateEmail:@"sam@example.com"];