Fundamental Operations
Explore the fundamental operations that govern the lifecycle of variables in D programming. Understand how initialization reserves memory and sets initial values, how assignment updates variables, and how finalization cleans up resources. This lesson clarifies differences between value and reference types, preparing you to manage variable lifetimes effectively in your D programs.
We'll cover the following...
Regardless of its type, there are three fundamental operations throughout the lifetime of a variable:
- Initialization: The start of its life
- Assignment: Changing its value as a whole
- Finalization: The end of its life
To be considered a variable, it must first be initialized. There may be final operations for some types. The value of a variable may change during its lifetime.
Initialization
Every variable must be initialized before being used. Initialization involves two steps:
- Reserving space for the variable: This space is where the value of the variable is stored in memory.
- Construction: This step involves setting the first value of the variable on that space (or the first values of the members of structs and classes).
Every variable lives in a place in memory that is reserved for it. Some of the code that the compiler generates is about reserving space for each variable. Let’s consider the following variable:
int speed = 123;
As we have seen in the value types and reference types chapter, we can imagine this variable living on some part of the memory:
The memory location (0x00345FeB) that a variable is placed at is called its address. In a sense, the variable ...