+ dictionaryWithCapacity:

Creates and returns a mutable dictionary, initially giving it enough allocated memory to hold a given number of entries.

Example

	NSMutableDictionary *dict =  [NSMutableDictionary dictionaryWithCapacity:1];
    NSLog(@"%@",dict);

Output

2014-03-22 18:16:58.178 iOS-Tutorial[2727:a0b] {
}

- initWithCapacity:

Initializes a newly allocated mutable dictionary, allocating enough memory to hold numItems entries.

Example

 
	NSMutableDictionary *dict =  [[NSMutableDictionary alloc] initWithCapacity:1];		
	NSLog(@"%@",dict);

Output

2014-03-22 18:16:58.178 iOS-Tutorial[2727:a0b] {
}

- init

Initializes a newly allocated mutable dictionary.

Example

	NSMutableDictionary *dict =  [[NSMutableDictionary alloc] init];		
	NSLog(@"%@",dict);

Output

2014-03-22 18:16:58.178 iOS-Tutorial[2727:a0b] {
}

+ dictionaryWithSharedKeySet:

Creates a mutable dictionary which is optimized for dealing with a known set of keys.

Example

	id sharedKeySet = [NSDictionary sharedKeySetForKeys:@[@"key1", @"key2"]]; // returns NSSharedKeySet
    NSMutableDictionary *dict = [NSMutableDictionary dictionaryWithSharedKeySet:sharedKeySet];
    dict[@"key1"] = @"Eezy";
    dict[@"key2"] = @"Tutorials";
    //We can an object thats not in the shared keyset
    dict[@"key3"] = @"Website";
    NSLog(@"%@",dict);

Output

2014-03-22 13:19:09.686 iOS-Tutorial[929:a0b] {
    key1 = Eezy;
    key2 = Tutorials;
    key3 = Website;
}

Adding Entries to a Mutable Dictionary

- setObject:forKey:

Adds a given key-value pair to the dictionary.

Example

	NSMutableDictionary *dict =  [NSMutableDictionary dictionary];
    [dict setObject:@"Eezy" forKey:@"Key1"];
    NSLog(@"%@",dict);

Output

2014-03-22 18:25:46.035 iOS-Tutorial[2745:a0b] {
    Key1 = Eezy;
}

- setObject:forKeyedSubscript:

Adds a given key-value pair to the dictionary.

Example

	NSMutableDictionary *dict =  [NSMutableDictionary dictionary];
    [dict setObject:@"Eezy" forKeyedSubscript:@"Key1"];
    NSLog(@"%@",dict);

Output

2014-03-22 18:29:26.543 iOS-Tutorial[2761:a0b] {
    Key1 = Eezy;
}

- setValue:forKey:

Adds a given key-value pair to the dictionary.

Example

	NSMutableDictionary *dict =  [NSMutableDictionary dictionary];
    [dict setValue:@"Eezy" forKey:@"Key1"];
    NSLog(@"%@",dict);

Output

2014-03-22 18:30:34.190 iOS-Tutorial[2775:a0b] {
    Key1 = Eezy;
}

- addEntriesFromDictionary:

Adds to the receiving dictionary the entries from another dictionary.

Example

	NSDictionary *tempDictionary = @{@"key1":@"Eezy",@"key2": @"Tutorials"};
	NSMutableDictionary *dict =  [NSMutableDictionary dictionary];
    [dict addEntriesFromDictionary:tempDictionary];
    NSLog(@"%@",dict);

Output

2014-03-22 18:31:57.039 iOS-Tutorial[2788:a0b] {
    key1 = Eezy;
    key2 = Tutorials;
}

- setDictionary:

Sets the contents of the receiving dictionary to entries in a given dictionary.

Example

	NSDictionary *tempDictionary = @{@"key1":@"Eezy",@"key2": @"Tutorials"};
	NSMutableDictionary *dict =  [NSMutableDictionary dictionary];
    [dict setDictionary:tempDictionary];
    NSLog(@"%@",dict);

Output

2014-03-22 18:31:57.039 iOS-Tutorial[2788:a0b] {
    key1 = Eezy;
    key2 = Tutorials;
}

Removing Entries From a Mutable Dictionary

- removeObjectForKey:

Removes a given key and its associated value from the dictionary.

Example

	NSMutableDictionary *dict =  [NSMutableDictionary dictionaryWithDictionary:@{@"key1":@"Eezy",@"key2": @"Tutorials"}];
    [dict removeObjectForKey:@"key1"];
    NSLog(@"%@",dict);

Output

2014-03-22 18:34:20.150 iOS-Tutorial[2814:a0b] {
    key2 = Tutorials;
}

- removeAllObjects

Empties the dictionary of its entries.

Example

	NSMutableDictionary *dict =  [NSMutableDictionary dictionaryWithDictionary:@{@"key1":@"Eezy",@"key2": @"Tutorials"}];
    [dict removeAllObjects];
    NSLog(@"%@",dict);

Output

2014-03-22 18:34:57.068 iOS-Tutorial[2827:a0b] {
}

- removeObjectsForKeys:

Removes from the dictionary entries specified by elements in a given array.

Example

	NSMutableDictionary *dict =  [NSMutableDictionary dictionaryWithDictionary:@{@"key1":@"Eezy",@"key2": @"Tutorials"}];
    [dict removeObjectsForKeys:@[@"key1"]];
    NSLog(@"%@",dict);

Output

2014-03-22 18:35:54.197 iOS-Tutorial[2838:a0b] {
    key2 = Tutorials;
}

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