Declaration statement-memory is reserve

Question

When using a declaration statement how memory is reserved?

Answer 1

Memory is reserved by using data type in variable declaration. A programming language execution has predefined sizes for its data types.

For illustration, in C# the declaration int i; will reserve 32 bits for variable i.

A pointer declaration reserves memory for address or pointer variable, however not for the data that it will point to. The memory for the data pointed by the pointer has to be assigned at runtime.

The memory reserved by compiler for simple variables and for storing pointer address is assigned on stack, while the memory allocated for pointer referenced data at runtime is allocated on heap.