NSMutableDictionary的使用方法

字典也和数组,字符串一样也有一个可变的子类, 只是涉及的方法名不一样, 但是原理都差不多.

涉及到的方法:

removeObjectForKey: 删除指定的键值对(PS: 这里输入的只能是键, 输入键会删掉键和值, 但是输入值是不会发生任何事情的).

 

下面我们来看看例子:

#import <Foundation/Foundation.h>

int main(int argc, const char * argv[]) {
    @autoreleasepool {
        NSMutableDictionary *dicti = [NSMutableDictionary new];
        [dicti setObject:@"Five" forKey:@"5"];
        [dicti setObject:@"Four" forKey:@"4"]; //添加指定的键值对
//        [dicti setObject:@"Five" forKey:@"5"];
        //添加键值对和删除键值对的时候没有说是插入到哪里, 和删除哪一个, 因为字典中的键值对是不讲究位置的.
        NSLog(@"dicti = %@", dicti);
        
        
        //removeObjectForKey:删除对应的键值对.
        //删除键值对也是同样不将就顺序.
//        [dicti removeObjectForKey:@"4"];
        [dicti removeObjectForKey:@"5"];

        NSLog(@"diciti = %@", dicti);
        
        [dicti release];
    }
    return 0;
}

输出来的结果:

2014-10-13 21:16:31.843 NSMutableDictionary[6749:303] dicti = {
    4 = Four;
    5 = Five;
}
2014-10-13 21:16:31.844 NSMutableDictionary[6749:303] diciti = {
    4 = Four;
}
Program ended with exit code: 0