Call By Value and Call by Reference in C#

Understand the difference between call by value and call by reference in C#, and how each affects the way data is passed to methods.

What is Call by Value?

In call by value, a copy of the variable's data is passed to the method. Any changes made to the parameter inside the method have no effect on the original variable back in the calling code.

What is Call by Reference?

In call by reference, using the ref or out keywords, the method receives a reference to the original variable itself, meaning any changes made inside the method directly affect the original value.

Value Types vs Reference Types

It's important to note that even reference types like classes are passed by value by default, meaning the reference itself is copied, though both copies still point to the same underlying object unless ref is explicitly used.

Choosing the Right Approach

Call by value is the safer default for most scenarios since it prevents unintended side effects, while call by reference is useful when a method genuinely needs to modify the caller's original variable or return multiple values.