NSMutableDictionary *mutdic=[[NSMutableDictionary alloc]initWithObjectsAndKeys:@"Jay",@"name",@"22",@"age",@"F",@"gender",nil];
//添加
NSDictionary *dic=[NSDictionary dictionaryWithObject:@"188" forKey:@"height"];
[mutdic addEntriesFromDictionary:dic];
[mutdic setValue:@"66" forKey:@"weight"];
//创建空的可变字典
NSMutableDictionary *nulldic=[NSMutableDictionary dictionary];
//将字典newdic设置与字典mutdic对象相同
[nulldic setDictionary:mutdic];
//将字典中对应的key的值删除
[nulldic removeObjectForKey:@"name"];
NSArray *keys=[NSArray arrayWithObjects:@"height",@"weight", nil];
[nulldic removeObjectsForKeys:keys];
//删除全部
[nulldic removeAllObjects];
[nulldic setDictionary:mutdic];