Check out example codes for "free in c". It will help you in understanding the concepts better.
Code Example 1
//malloc or "memory allocation" reserves a part of the memory pointer = (cast-type*) malloc(byte-size) //Example ptr = (int*) malloc(100 * sizeof(int)); Since the size of int is 4 bytes, this statement will allocate 400 bytes of memory. And, the pointer ptr holds the address of the first byte in the allocated memory.
Code Example 2
the C library function void free(void *ptr) deallocates the memory previously allocated by a call to calloc, malloc, or realloc.
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