c - 如何创建在内存中分配的数组

Question

我使用下面的代码来创建动态内存。

unsigned int *mem  ;
mem = (unsigned int*) malloc(mallocSize);

但是，我更喜欢创建一个指针数组。每个指针都会链接到其中一个内存块。

Answer 1

but I prefer to create an array of pointers each pointer links to one of the memory block above

unsigned int **mem = (unsigned int **)malloc(sizeof(unsigned int *) * number_of_pointers);
// memset(mem, NULL, sizeof(unsigned int *) * number_of_pointers); // recommend it but not needed here, we always set NULL for safety.
for (int index = 0; index < number_of_pointers; index++)
    mem[index] = (unsigned int *)malloc(sizeof(unsigned int) * number_of_ints);

访问单个元素mem[row_index][column_index]

取消分配，减少或消除内存泄漏。

for (int index = 0; index < number_of_pointers; index++)
    free(mem[index]);
free(mem);

根据经验，无论如何，对我来说，free 应该像 malloc 一样频繁地调用