How to Make Custom Folder Icon in MAC

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Email Validation in Objective C

-(BOOL)emailValidation:(NSString *)email {
    BOOL result;
    //checking email validation
    NSString *emailRegEx = @"[A-Z0-9a-z._-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,4}";
    NSPredicate *emailTest = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", emailRegEx];
    //Valid email address
    if ([emailTest evaluateWithObject:email] == YES){
        NSLog(@"Valid email address");
        result=NO;
    }else{
        NSLog(@"Invalid email address");
        result=YES;
    }
    return result;
}

MD5 in Objective C

Just Import  CommonCrypto/CommonDigest.h and following method returns md5 string.

 #import <CommonCrypto/CommonDigest.h>

- (NSString *)convertIntoMD5:(NSString *) string{
    const char *cStr = [string UTF8String];
    unsigned char digest[16];

    CC_MD5( cStr, strlen(cStr), digest ); // This is the md5 call
   
    NSMutableString *resultString = [NSMutableString stringWithCapacity:CC_MD5_DIGEST_LENGTH * 2];
   
    for(int i = 0; i < CC_MD5_DIGEST_LENGTH; i++)
        [resultString appendFormat:@"%02x", digest[i]];
    return  resultString;
}