iOS如何判断NSDictionary是否包含某个key

NSDictionary *dictionary = [NSDictionary dictionaryWithObjectsAndKeys:@"bozhi",@"name","women",@"sex",nil];

    if ([dictionary objectForKey:@"age"]) {

        NSLog(@"字典包含key:name");

    }

    else{

        NSLog(@"字典不包含key:name");

    }