Generating a Random value in objective-c

Hi, today lets see how to generate a random number from zero to a given Number.

/ Get random value between 0 and 99
int x = arc4random() % 100;
 
// Get random number between 500 and 1000
int y =  (arc4random() % 501) + 500); 

Now Lets see how to Generate a random alpha numeric value.  This is usually required for genrating passwords/ IDs.

   NSString *letters = @"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";

-(NSString *) genRandStringLength: (int) len {

    NSMutableString *randomString = [NSMutableString stringWithCapacity: len];

    for (int i=0; i<len; i++) {
         [randomString appendFormat: @"%C", [letters characterAtIndex: arc4random() % [letters length]]];
    }

    return randomString;
}

Getting Current Date into a String (ios)

Hi Lets see the simple code to get current time

    //Get current date

    NSDate *date = [NSDate date];



    // format it

    NSDateFormatter *dateFormat = [[NSDateFormatter alloc]init];

    [dateFormat setDateFormat:@"MMM dd, yyyy"];



    // convert it to a string

    NSString *dateString = [dateFormat stringFromDate:date];

    // free up memory

    [dateFormat release];





    //Try it

    NSLog(@"Todays date is = %@",dateString);




   This is what i got : 

Todays date is = Aug 28, 2012

Cheers

initwitharray VS arrayWithObjects

InitWith Object Syntax:
NSArray *bar = [[NSArray alloc] initWithObjects:@"hai",@"how",@"are",@"you",nil];

Array With Objects Syntax:

NSArray *tempArray = [NSArray arrayWithObjects:@"hai",@"how",@"are",@"you",nil];

Result= return [[[NSArray alloc] initWithObjects:@"hai",@"how",@"are",@"you",nil] autorelease]

So here the array returned is auto-released. Thats the only difference.