为数组重新分配内存c ++

Question

I was looking on C++ reference and found the dynamic memory management and was looking at the function that reallocate memory and I was wondering if this function could be used to make an array bigger I think that is what they mean but I really don't understand this line

more_numbers = (int*) realloc (numbers, count * sizeof(int));

this appears in the example on cplusplus reference so here is my question in a nutshell

can realloc() be used to make an array bigger? thanks :)

Answer 1

Only if the memory for the array was allocated via malloc() , calloc() , or realloc() earlier. Otherwise you're asking for trouble.

Answer 2

"The function may move the memory block to a new location, in which case the new location is returned". Even though it preserves the data in your block, any pointers to the objects inside this block may become invalid.