對象-ios 往可變字典添加object會覆蓋到上一個key的值啊！！怎麼解決！有代碼~~

ios 往可變字典添加object會覆蓋到上一個key的值啊！！怎麼解決！有代碼~~

self.arr=[NSMutableArray new];
self.dic=[NSMutableDictionary new];
[self.arr addObjectsFromArray:@[@"1",@"2",@"3"]];
[self.dic setObject:self.arr forKey:@"key1"];

[self.arr removeAllObjects];
[self.arr addObjectsFromArray:@[@"3",@"4",@"5"]];
[self.dic setObject:self.arr forKey:@"key2"];

NSLog(@"%@",self.dic);



    輸出結果：
    {
key1 =     (
    3,
    4,
    5
);
key2 =     (
    3,
    4,
    5
);

}

最佳回答：

[self.arr removeAllObjects];
->
self.arr=[NSMutableArray new];