Check whether NSString starts with aplhabet letter only.

+(BOOL)validateFirstCharacterAsAlphabet:(NSString *)str;

{

    NSRange first = [str rangeOfComposedCharacterSequenceAtIndex:0];

    NSRange match = [str rangeOfCharacterFromSet:[NSCharacterSet letterCharacterSet] options:0 range:first];

    if (match.location != NSNotFound) {

        // String starts with a letter

        return YES;

    }

    return NO;

    

}

Copy a UIView from xib and programmatically repeat it using NSKeyedArchiver and NSKeyedUnarchiver.

Lets create a _contactView in .h file using IBOutlet, and connect it in .xib file.

Connect it to the _contactView.

In .m:

//The following line will create a similar view as _contactView in the XIB;

 id copyOfView = [NSKeyedUnarchiver unarchiveObjectWithData:[NSKeyedArchiver archivedDataWithRootObject:_contactsView]];

// Repeat the view to generate multiple copies and add to the scroll view.

for (int i =0; i<_contactArray.count; i++) {

        UIView* tempView ;//= [[UIView alloc]init];

        id copyOfView = [NSKeyedUnarchiver unarchiveObjectWithData:[NSKeyedArchiver archivedDataWithRootObject:_contactsView]];

        tempView = copyOfView;

        tempView.tag = i;

        [tempView setFrame:CGRectMake(xOffset, yOffset, width, height)];

        yOffset += ySpacing+height;

        [_contactScrollView addSubview:tempView];

    }

    [_contactScrollView setContentSize:CGSizeMake(_contactsView.frame.size.width, _contactsView.frame.size.height*(_contactArray.count+1))];

Open other apps from iOS app using URL scheme. Open google maps, mail from the app, call a number, send sms using Xcode.

Use openURL: function of UIApplication.

[[UIApplication sharedApplication] openURL:[NSURL URLWithString:urlText]];

Open The Google Maps:

// Create string for the place ...
NSString* placeStr = @"1 Infinite Loop, Cupertino, CA 95014";
// Encode URL encode
placeStr =  [addressText stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
// Now create the URL string ...
NSString* urlString = [NSString stringWithFormat:@"http://maps.google.com/maps?q=%@", placeStr];
// use openURL to launch the app ...
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:urlText]];

Mail from the app:

[[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"mailto://info@example.com"]];

Call a number:

[[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"tel://9876543210"]];


Send SMS:

[[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"sms:55555"]];




Open App Store:

[[UIApplication sharedApplication]  openURL:[NSURL URLWithString:@"https://itunes.apple.com/en/app/apple-store/id375380948?mt=8"]];

Vibrate UIView. Add Shivering effect to the view.

+ (void)vibrateView:(UIView*)view

{

    CABasicAnimation *shiverAnimationR;

    shiverAnimationR = [CABasicAnimation animationWithKeyPath:@"transform.rotation.z"];

    shiverAnimationR.toValue = [NSNumber numberWithFloat:DEGREES_TO_RADIANS(1)];

    //shiverAnimationR.toValue = [NSNumber numberWithFloat:DEGREES_TO_RADIANS(-10)];

    shiverAnimationR.duration = 0.1;

    shiverAnimationR.repeatCount = 1000000.0; // Use A high Value

    shiverAnimationR.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseIn];

    [view.layer addAnimation: shiverAnimationR forKey:@"shiverAnimationR"];

    CABasicAnimation * shiverAnimationL;

    shiverAnimationL = [CABasicAnimation animationWithKeyPath:@"transform.rotation.z"];

    //shiverAnimationL 2.toValue = [NSNumber numberWithFloat:DEGREES_TO_RADIANS(10)];

    shiverAnimationL.toValue = [NSNumber numberWithFloat:DEGREES_TO_RADIANS(-1)];

    shiverAnimationL.duration = 0.1;

    shiverAnimationL.repeatCount = 1000000.0;

    shiverAnimationL.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseIn];

    [view.layer addAnimation: shiverAnimationL forKey:@"shiverAnimationL"];

}

Rotate the UIView clockwise. Rotate or swing UIView in circular manner.

+(void)rotateViewLikeCircle:(UIView*)view rotation:(int)numberOfRotation 

{

    CABasicAnimation *rotationAnimation;

    rotationAnimation = [CABasicAnimation animationWithKeyPath:@"transform.rotation.z"];

    rotationAnimation.toValue = [NSNumber numberWithFloat:DEGREES_TO_RADIANS(180)];

    rotationAnimation.duration = 0.75;

    rotationAnimation.repeatCount = numberOfRotation;

    rotationAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseIn];

    [view.layer addAnimation:rotationAnimation forKey:@"rotationAnimation"];

}

Also don't forget to add the macros for converting degree to radian and visa-versa.

#define DEGREES_TO_RADIANS(degree) (M_PI * degree / 180.0)

#define RADIANS_TO_DEGREES(radians) ((radians) * (180.0 / M_PI))