如何从函数返回动态分配的指针数组？ [英] How do I return a dynamically allocated pointer array from a function?

问题描述

我现在开始在类中的动态内存分配，并有一个确定的理解，但不能完全使用它。我觉得我可能不会这么伟大与指针：p

I am now starting Dynamic Memory Allocation in class and have a ok understanding of it but can't completely use it properly. I feel like I may not be so great with pointers either :p

我的教师给了指令创建一个名为readArray的函数，将提示用户一个数字使用大小为动态创建该大小的整数数组。然后我将新数组分配给一个指针。然后我应该提示用户填充数组。然后我应该返回新创建的数组和大小。

My instructor gave instructions to create a function named readArray that will prompt the user for a number to use as a size to dynamically create a integer array of that size. I am then to assign the new array to a pointer. I then am supposed to prompt the user to fill the array. I then am supposed to return both the newly created array and the size.

我不知道如何返回数组，而我想当动态分配内存你应该在使用它之后删除分配以防止泄漏。

I can not figure out how to return the array though, and I thought when dynamically allocating memory you were supposed to delete the allocation after using it to prevent leaks.

数组和大小必须返回到main，所以我可以将它传递给其他函数，如排序函数。

The array and size must be returned to main so I can pass it to other functions such as a sorting function.

我会非常感谢任何帮助，因为我的思维过程中，这将继续走错了方向。

I would greatly appreciate any help I can get as my thought process with this keeps going in the wrong direction.

#include <iostream>
using namespace std;

int* readArray(int&);
void sortArray(int *, const int * );

int main ()
{
   int size = 0;
   int *arrPTR = readArray(size);
   const int *sizePTR = &size;
   sortArray(arrPTR, sizePTR);

   cout<<arrPTR[1]<<arrPTR[2]<<arrPTR[3]<<arrPTR[4];

        system("pause");
        return 0;
}


int* readArray(int &size)
{
   cout<<"Enter a number for size of array.\n";
   cin>>size;
   arrPTR = new int[size];

   for(int count = 0; count < (size-1); count++)
   {    
       cout<<"Enter positive numbers to completely fill the array.\n";
       cin>>*(arrPTR+count);
   }

   return arrPTR;
}

推荐答案

返回数组：declare readArray（） as int * readArray（） [return an int * 而不是大小，而不是 int ]，并返回 arrPTR c $ c>。这样，你返回 arrPTR 指向的动态分配的数组。

To return an array: declare readArray() as int* readArray() [return an int* instead of an int], and return arrPTR instead of size. This way, you return the dynamically allocated array which arrPTR points to.

关于删除：使用数组，你应该删除它。在您的示例中，在 main（）函数中返回0

确保自从您为 new [] 分配内存后，您还应该使用 delete [] ，否则您的计划将有内存泄漏。

Regarding the delete: When you are done using the array, you should indeed delete it. In your example, do it before return 0 in your main() function.
Make sure that since you allocated memory with new[], you should also free it with delete[], otherwise - your program will have a memory leak.

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