Memory Allocation Methods Quiz

Memory Allocation

• There are two ways to allocate memory for storing data: compile time allocation (static allocation) and run time allocation (dynamic allocation)
• Compile time allocation is done by the compiler, where the exact size and storage must be known at compile time, and the size of arrays must be constant
• Run time allocation is done dynamically within the program run, and the exact space or number of items does not have to be known by the compiler in advance

Dynamic Memory Allocation

• Dynamic memory allocation allows programmers to allocate storage space while the program is running
• It requires two criteria: creating dynamic space in memory and storing its address in a pointer
• The free store is an area of memory available in the C++ run-time environment to handle dynamic memory allocation
• The new operator is used to allocate memory at run time and returns the address of the space allocated
• Memory de-allocation is also a part of dynamic memory allocation, where the programmer must clean up dynamically created space using the delete operator

Pointers and Dynamic Memory Allocation

• Arrays are limited in size and cannot be adjusted during the program run
• Pointers are used to build dynamic data structures from small pieces, allowing for dynamic growth
• A pointer is the address value of a memory location
• Pointers can be declared using the syntax: Type * variable-name;
• Operations on pointers include:
  • The address-of operator (&) to get the memory address of a variable
  • The contents of operator (*) to get the variable pointed to by a pointer