dynamic memory in c

Dynamic memory allocation in C allows the program to allocate memory at runtime. This means that the program can request memory from the operating system as needed, rather than having to allocate a fixed amount of memory at compile time.

To allocate memory dynamically in C, you can use the malloc() function. This function takes the number of bytes to allocate as an argument and returns a pointer to the allocated memory. Here is an example:

int *ptr;
ptr = (int) malloc(5  sizeof(int));

In this example, we declare a pointer ptr of type int. We then use malloc() to allocate memory for 5 integers. The sizeof(int) expression is used to determine the size of each integer in bytes. The malloc() function returns a void pointer, so we need to cast it to the appropriate type before assigning it to ptr.

To free the dynamically allocated memory when it is no longer needed, you can use the free() function. Here is an example:

free(ptr);

In this example, we use the free() function to release the memory pointed to by ptr. It is important to note that once memory is freed, it should not be accessed again.

Dynamic memory allocation can be useful when the size of the data needed by the program is not known at compile time or when memory needs to be allocated and deallocated dynamically during program execution. However, it is important to manage dynamically allocated memory carefully to avoid memory leaks or accessing freed memory.