What is the difference between delete and delete [] in C++?

 In C++, delete is used to deallocate memory that was allocated using the new operator for a single object, while delete[] is used to deallocate memory that was allocated using the new operator for an array of objects.

Here's an example of using delete to deallocate memory for a single object:

int* ptr = new int; // allocate memory for a single int
*ptr = 5; // set the value of the int
delete ptr; // deallocate the memory

In this example, we allocate memory for a single integer using the new operator and assign a value to it. Then, we deallocate the memory using the delete operator.

And here's an example of using delete[] to deallocate memory for an array of objects:

int* arr = new int[5]; // allocate memory for an array of 5 ints
for(int i = 0; i < 5; i++) {
    arr[i] = i; // set the value of each element in the array
}
delete[] arr; // deallocate the memory

In this example, we allocate memory for an array of 5 integers using the new operator and assign values to each element of the array. Then, we deallocate the memory using the delete[] operator.

Using delete instead of delete[] or vice versa can lead to undefined behavior, which can cause crashes or other unexpected errors in your program. Therefore, it's important to use the correct operator depending on how the memory was allocated.