Objective-C字典NSDictionary与可变字典NSMutableDictionary使用

//通过类对象创建字典
    NSDictionary *dic = [[NSDictionary alloc] initWithObjects:@[@1,@2,@3] forKeys:@[@"A",@"B",@"C"]];
    //通过键取字典中值
    NSLog(@"count:%lu,A:%@,B:%@,C:%@",
          dic.count,
          [dic objectForKey:@"A"],
          [dic objectForKey:@"B"],
           [dic objectForKey:@"C"]);
    //一值一键,先值后键
    NSDictionary *dic1 = [[NSDictionary alloc] initWithObjectsAndKeys:@1,@"A",@2,@"B",@3,@"C",@4,@"D", nil];//value,key
    //遍历值
    for (id v in dic1.objectEnumerator) {
        NSLog(@"%@",v);
    }
    //遍历键
    for (id v in dic1.keyEnumerator) {
        NSLog(@"%@",v);
    }
    
    //通过现有字典创建可扩展字典
    NSMutableDictionary *mdic = [NSMutableDictionary dictionaryWithDictionary:dic1];
    //向可扩展字典中添加键值对
    [mdic setObject:@5 forKey:@"E"];
    
    //创建不可扩展字典
    NSDictionary *dic2 = [NSDictionary dictionaryWithObjects:@[@6,@7,@8] forKeys:@[@"F",@"G",@"H"]];
    //向可扩展字典中添加现有字典
    [mdic addEntriesFromDictionary:dic2];
    //遍历字典
    for (id x in mdic) {
        NSLog(@"%@",x);
    }
    
    
    //创建可扩展集合对象
    NSMutableArray *numArray = [[NSMutableArray alloc] init];
    //向集合添加数据
    for (int i=0; i<100; i++) {
        //创建数字对象
        NSNumber *num1 = [[NSNumber alloc]initWithInt:i];
        [numArray addObject:num1];
    }
    //正向遍历集合
    for (id n in numArray.objectEnumerator) {
        NSLog(@"%@",n);
    }
    //反向遍历集合
    for (id n  in numArray.reverseObjectEnumerator) {
        NSLog(@"%@",n);
    }
    
    //大数使用NSDecimalNumber
    [numArray removeAllObjects];
    for (int i=1; i<101; i++) {
        //创建数字对象
        NSNumber *num1 = [[NSDecimalNumber alloc]initWithInt:i*999999];
        [numArray addObject:num1];
    }
    //正向遍历集合
    for (id n in numArray.objectEnumerator) {
        NSLog(@"%@",n);
    }
    //反向遍历集合
    for (id n  in numArray.reverseObjectEnumerator) {
        NSLog(@"%@",n);
    }