What is scope in C#?

The scope in C# defines the accessibility of variables, methods, and types within a certain part of the program. It restricts where in the code a particular identifier can be used.

Main scopes:

• Block Scope: Variables declared inside curly braces { } are only accessible within that block.
• Method Scope: Variables and parameters declared inside a method are only accessible within that method.
• Class/Struct Scope: Members of a class or struct (fields, properties, methods) are accessible depending on access modifiers (public, private, protected, internal).
• Namespace Scope: Types declared within a namespace are accessible within that namespace and other namespaces where using is used.
• Assembly Scope: Types with the internal modifier are only accessible within the current assembly.

Example of block scope:

public void ExampleMethod()
{
    int x = 10; // x is only accessible inside ExampleMethod
    if (x > 5)
    {
        int y = 20; // y is only accessible inside the if block
        Console.WriteLine(y);
    }
    // Console.WriteLine(y); // Compilation error: y is not accessible here
}