What's the Difference Between Variables, Objects, and References in Programming?

The difference between variables, objects and references in programming

variables, objects, and references are the basic concepts in programming. Understanding their differences are essential for effective software development.

Variables

Variables are containers of the storage value. In the provided sample code, "X" is a variable that saves integer 12. Different from objects that stay in memory and save actual data, variables are just storage of references to these memory locations.

Object

On the contrary, the object is an instance that has defined types or classes. They occupy memory space and encapsulate data and behavior. The "DOG" variable in the code refers to the "DOG" type object in memory. Quote

Quote the path of acting as the object. Quote do not save actual data, but save the memory address of the objects they point. This method allows multiple variables to reference the same object without creating duplicate copies.

analogy

In order to further clarify this concept, consider the following analogy:

Variables are like a piece of paper with an address.

The reference is the address itself, pointing to the object.

Object is the actual house of this location.

Multiple references can cause different variables to point to the same object, similar to the keys of the same house by multiple people.
Value type and reference type

In the code example, "X" is a value type variable, which means that it directly stores the integer value. "DOG" is a reference type variable, which contains a reference to the actual "DOG" object. The size of the value type variable is fixed, and the size of the reference type variable is changed according to the objects they reference.

In short, the variable preservation value or reference, the object is an entity with data and behavior, quoting the method of indirect access objects by storing the memory address of the storage object. Understanding these differences can improve the maintenance, efficiency and organizationalability of the code.

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