C# to Objective C by example #7

gistfile1.m

-(void) dictionaryExample
{
	// NSDictionary exists, but you can`t add/remove items to it once it`s initialised
	// NSMutableDictionary inherits from NSDictionary
	// More info: http://developer.apple.com/documentation/Cocoa/Conceptual/Collections/Collections.html
	NSMutableDictionary *dictionary = [NSMutableDictionary dictionary];

	// This is another way to initialise the dictionary, remember to use nil at the end
	// nil is just another definition of NULL
	NSMutableDictionary *dictionary2 = [NSMutableDictionary dictionaryWithObjectsAndKeys:@"obj1",@"key1",@"obj2",@"key2",nil];
	
	// Adding keys
	[dictionary setObject: @"my object" forKey:@"key"];
	[dictionary setObject: @"my object" forKey:@"key2"];
	
	// Getting by a single key
	NSLog(@"%@", [dictionary objectForKey:@"key"]);

	// Enumerating
	for (NSString *key in dictionary)
		NSLog(@"key: %@, value: %@", key,[dictionary objectForKey:key]);
	
	// Lookups would be performed using enumeration, there is no IndexOf or equivalent.

	// Deleting
	[dictionary removeObjectForKey:@"key"];
	
	// Count comes from the base, NSDictionary
	NSLog(@"Dictionary count: %i", [dictionary count]);
}