NSDictionary - Need to check whether dictionary contains key-value pair or not

Question

Hello Every one.

I just need to ask something as follow. Suppose I am having a dictionary.

NSMutableDictionary *xyz=[[NSMutableDictionary alloc] init];
[xyz setValue:@"sagar" forKey:@"s"];
[xyz setValue:@"amit" forKey:@"a"];
[xyz setValue:@"nirav" forKey:@"n"];
[xyz setValue:@"abhishek" forKey:@"a"];
[xyz setValue:@"xrox" forKey:@"x"];

Now, I need to check as follows

[xyz does contains key "b" value ?? pair or not?

Question is How?

The other question is How to just count total key-value pair?

Say for example NSInteger mCount=[xyz keyCounts];

Thanks in advance for sharing your great knowledge.

Sagar

Answer 1

Just ask it for the objectForKey:@"b". If it returns nil, no object is set at that key.

if ([xyz objectForKey:@"b"]) {
    NSLog(@"There's an object set for key @\"b\"!");
} else {
    NSLog(@"No object set for key @\"b\"");
}

Edit: As to your edited second question, it's simply NSUInteger mCount = [xyz count];. Both of these answers are documented well and easily found in the NSDictionary class reference ([1] [2]).