是否可以在运行时在堆上创建一个数组，然后在需要时分配更多的空间？ [英] Is it possible to create an array on the heap at run-time, and then allocate more space whenever needed?

问题描述

让我说

char *a;
a = new char[4];

现在，是否可以进一步扩展数组的大小？

Now, is it possible to extend the size of the array further?

说我想把 a [0] 中的任何值保留到 a [3] 但现在我想为 a [4] 和 a [5] 在C ++中？

Say I want to keep any values I put inside a[0] to a[3] but now I want more space for a[4] and a[5] etc. Is that possible in C++?

起初我觉得可能只是：

char* a[10];
a[0] = new char[size];

每当需要更多空间时，我可以转到 a [1] code>并分配更多空间。这是我目前唯一可以想到的选择。

Whenever more space is needed I can go to a[1] and allocate more space. This is the only alternative I can think of at the moment.

推荐答案

不幸的是，在C ++中是不可能的。你必须分配一个新区域并将旧区域复制到新区域。

Unfortunately it's not possible in C++. You have to allocate a new area and copy the old into the new.

但是，C ++还有其他功能，例如 std :: vector ，这减轻了手动处理这些事情的需要。

However, C++ have other facilities, like std::vector, that alleviates the need to manually handle these things.

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