Static Variable

Normally, stack memory address will be destroyed:

Stack memory

Normally, local variables will be stored in stack memory and will be destroyed after there is no reference to that local variables anymore

This will happen especially in the functions

int* stackMemoryAddress() {
    int myNumber { 10 };
    return &myNumber;
}

or

int* stackMemoryAddress() {
    int myNumber { 10 };
    int *ptr = &myNumber;
    return ptr;
}

cout << *stackMemoryAddress() << endl;

Note that in here the myNumber will be destroyed and the program might crash. However, sometimes it might works.

There are 2 options to fix this

Static variables

int* stackMemoryAddress() {
    static int myNumber { 10 };
    return &myNumber;
}

cout << *stackMemoryAddress() << endl;

Doing this would move the variable to the heap space instead of stack

Malloc this variables

Another option is to malloc this, this will in turn store this variable in heap

int* stackMemoryAddress() {
    int myNumber { 10 };
    int *ptr = (int*) malloc(sizeof(myNumber));
    ptr = &myNumber;
    return ptr;
}

cout << *stackMemoryAddress() << endl;