int **a=new int*[m]
时间: 2023-08-28 20:06:32 浏览: 99
在C++中,`new int*[m]`会创建一个包含`m`个整型指针的数组,并返回指向该数组的指针。这意味着你创建了一个指向指针的指针。它的使用方式如下所示:
```cpp
int** a = new int*[m];
```
这将创建一个具有`m`个整型指针的数组,并将其起始地址赋值给指针`a`。你可以通过索引访问和修改这些指针,例如:
```cpp
a[0] = new int[n];
a[1] = new int[n];
// ...
```
在上述示例中,我们为每个指针分配了一个包含`n`个整数的数组。你可以使用这些指针分配和访问二维数组的元素。当你不再需要这个动态分配的二维数组时,记得释放内存,以防止内存泄漏:
```cpp
for (int i = 0; i < m; i++) {
delete[] a[i];
}
delete[] a;
```
通过循环释放每个指针指向的数组内存,然后再释放指向指针数组的内存。这样可以确保释放之前分配的内存空间。
相关问题
int** c; c = new int* [m+1];
This code creates a dynamic 2D array of integers with m rows and 1 column, and assigns the memory address of this array to the pointer variable c.
Note that the syntax for dynamically allocating a 2D array involves creating an array of pointers to arrays, where each pointer points to a dynamically allocated array of integers.
In this case, we are creating an array of m pointers, and each pointer will point to an array of 1 integer.
To access an element in this 2D array, we would use the syntax c[i][j], where i represents the row index and j represents the column index.
int *arr = (int*)malloc(sizeof(int)*501);这行代码是什么意思
这行代码是在C语言中动态分配了一个大小为sizeof(int)*501的内存空间,并将其地址赋给了指针变量arr。这意味着arr指针可以用来访问这个连续的内存区域,该区域可以存储501个int类型的数据。
#### 引用[.reference_title]
- *1* *2* [C/C++动态开辟数组【C++:new/delete(推荐):int *arr = new int[m];】【C++:vector】【C:malloc() & ...](https://blog.csdn.net/u013250861/article/details/125325044)[target="_blank" data-report-click={"spm":"1018.2226.3001.9630","extra":{"utm_source":"vip_chatgpt_common_search_pc_result","utm_medium":"distribute.pc_search_result.none-task-cask-2~all~insert_cask~default-1-null.142^v91^control_2,239^v3^insert_chatgpt"}} ] [.reference_item]
- *3* [int a[n]与int* a=(int*)malloc(sizeof(int)*n)的区别与联系](https://blog.csdn.net/weixin_39954922/article/details/113569953)[target="_blank" data-report-click={"spm":"1018.2226.3001.9630","extra":{"utm_source":"vip_chatgpt_common_search_pc_result","utm_medium":"distribute.pc_search_result.none-task-cask-2~all~insert_cask~default-1-null.142^v91^control_2,239^v3^insert_chatgpt"}} ] [.reference_item]
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