分配和释放内存(，) [英] Allocating and freeing memory (, )

问题描述

大家好，

假设我有一个结构数组，其大小是动态确定的:

Hello all,

Let''s assume that I have an array of structures, where the size is determined dynamically:

myStruct *pMyStruct = new myStruct[structSize];

并假设myStruct具有一个成员，该成员是指向字符串数组的指针:

and let''s assume that myStruct has a member which is a pointer to an array of strings:

string *pMyList;

我在代码中的某个地方分配了一个字符串临时数组:

Somewhere in the code I allocate a temporary array of strings:

string *pTempList = new string[listSize];

然后在代码中，我将该临时数组分配给myStruct的实例

and later in the code I assign that temporary array to the instances of myStruct

pMyStruct[i].pMyList = pTempList;

问题是一旦完成myStruct实例，我应该如何释放内存.
我是否需要在[structSize]上循环，以便为myStruct的每个实例释放pMylist，然后释放pMyStruct(然后释放pTempList)?

最好的问候，
Enrique

The question is how I should free the memory once I am done with the instances of myStruct.
Do I have to make a loop over [structSize] where I free pMylist for every instance of myStruct, then free pMyStruct (and then free pTempList)?

Best regards,
Enrique

推荐答案

Enrique，

您对std::string的询问不同，因为您知道它们具有自己的内部内存管理.

同样，标准C ++库为std::vector<>提供内部内存管理.

如果使用它而不是C数组，则您的问题将如下所示:
..假设myStruct具有一个成员，该成员是字符串数组的指针字符串向量:

Hi Enrique,

You don''t have the same interrogation about your std::strings because you know that they have their own internal memory management.

Similarly the Standard C++ Library provides std::vector<> with internal memory management.

If you used it instead of C arrays your question would look like:
.. let''s assume that myStruct has a member which is a pointer to an array of strings a vector of strings:

struct myStruct
{
	std::vector<std::string> MyList;
};

让我们假设我有一个一个数组一个结构的矢量，其大小是动态确定的:

Let''s assume that I have an array a vector of structures, where the size is determined dynamically:

std::vector<myStruct> MyStruct(structSize);

在代码中的某个地方，我分配了一个临时的 array 字符串向量:

Somewhere in the code I allocate a temporary array vector of strings:

std::vector<std::string> TempList(listSize);

，随后在代码中，我将该临时 array 向量分配给myStruct实例

and later in the code I assign that temporary array vector to the instances of myStruct

MyStruct[i].MyList = TempList;

问题是，一旦完成myStruct实例，我应该如何释放内存.

答案将是:您无需执行任何操作，所有内存都被释放在对象析构函数中，当它们超出范围时将被调用.

欢呼声，
AR

The question is how I should free the memory once I am done with the instances of myStruct.

The answer would be: You have nothing to do, all memory is deallocated in the objects destructors which are called when they get out of scope.

cheers,
AR

这篇关于分配和释放内存(，)的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！