C# Constant

C# is a variable whose value cannot be changed once it has been assigned. Constants are used when you want to define a value that remains the same throughout the lifetime of the program, providing clarity and reducing the risk of accidental changes to important values.

Characteristic of C# Constant

1. A constant must be assigned a value at the time of declaration.

2. The value of a constant cannot be changed after initialization.

3. Constants are implicitly static, meaning they belong to the type itself rather than to an instance of the class.

Syntax:

const data_type constant_name = value;

Explanation:

1. data_type can be any valid C# data type (e.g., int, double, string, etc.).

2. constant_name is the name of the constant.

3. value is the value assigned to the constant, and it must be a compile-time constant (i.e., a value that can be determined when the program is compiled).

Example:

using System;

class ConstantAppExample
{
    // Define constants for configuration
    public const string AppName = "MyApplication";
    public const double AppVersion = 1.0;

    static void Main()
    {
        // Display application configuration using constants
        Console.WriteLine($"Application Name: {AppName}");
        Console.WriteLine($"Application Version: {AppVersion}");
    }
}

Output:

Advantages of Using Constants

1. Code Maintainability: If a value is used repeatedly in multiple places, you can change the constant in one place instead of updating it in multiple locations.

2. Readability: Constants give meaningful names to values. For example, StatusCode.OK is clearer than using the raw integer 200.

3. Compile-time Checking: The compiler checks the value assignment at compile-time, which can reduce errors and unexpected behavior.

C# Constant – Interview Questions

C# Constant – Objective Questions (MCQs)

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