Question

The __________ operator is used to dynamically allocate memory.

Short answer

Answer: The "new" operator is used for dynamically allocating memory in C++. It allocates memory for an object or an array of objects on the heap and returns a pointer to the allocated memory. The syntax for using 'new' for memory allocation is `new datatype`, where datatype can be any valid C++ data type. For example: `int *ptr = new int;`. It is important to free the allocated memory using the "delete" operator when it is no longer needed to prevent memory leaks, e.g., `delete ptr;`. Dynamic memory allocation is crucial for various programming scenarios like data structures, where the exact amount of required memory is not known at compile time, and the memory can be allocated and deallocated during runtime as needed.

Step-by-step solution

Identifying the operator for dynamic memory allocation

The operator used for dynamically allocating memory is called the "new" operator in C++ and "malloc" in C.

Understand the usage of 'new' operator in C++

The "new" operator is used to allocate memory for an object or an array of objects on the heap. After allocation, 'new' returns a pointer to the allocated memory. The syntax for using 'new' to allocate memory for a variable is: `new datatype`, where datatype can be any valid C++ data type. For example: `int *ptr = new int;`

Understand the usage of 'malloc' function in C

The "malloc" function, found in the stdlib.h header file, is used to allocate a block of memory on the heap and returns a pointer to the first byte of the allocated memory. The syntax for using 'malloc' function is: `malloc(size_t size)`, where size is the number of bytes to be allocated. For example: `int *ptr = (int *)malloc(sizeof(int));`

Freeing allocated memory

It is important to free the allocated memory once it is no longer required, to prevent memory leaks. In C++, we use the "delete" operator to free the memory allocated by 'new'. In C, we use the "free" function to deallocate memory allocated by 'malloc'. For example, in C++: `delete ptr;` And in C: `free(ptr);`

Understand real-life usage

Dynamic memory allocation is crucial in various real-life programming scenarios, such as data structures like linked lists, trees, or graphs, where the exact amount of required memory is not known at compile time. By using dynamic memory allocation, we can allocate and deallocate memory during runtime as needed.