Understanding the Switch-Case Statement in C# (With Full Explanation and Example)

Introduction: What is a Switch-Case Statement in C#?

In C#, a switch-case statement provides a clean and organized way to execute different blocks of code based on the value of an expression or a variable.
It is often a better alternative to writing multiple if-else statements, especially when comparing a single value against many possibilities.

In this blog, you'll learn the syntax, explanation, and examples of using switch-case in C# programs.

Syntax of Switch-Case Statement

Here’s the general syntax for using a switch-case statement in C#:

switch (expression)
{
    case value1:
        // Code block executed when expression matches value1
        break;
        
    case value2:
        // Code block executed when expression matches value2
        break;
        
    // More cases...
    
    default:
        // Code block executed when no case matches
        break;
}

How Switch-Case Works:

The expression inside the switch is evaluated once.
The value is compared to each case value sequentially.
When a matching case is found, its code block is executed.
The break statement is used to stop executing further cases.
If no matching case is found, the default block (if provided) is executed.
The default case is optional but recommended for handling unexpected values.

Example: Switch-Case in Action

Here’s a simple example demonstrating the use of switch-case:

int day = 3;
string dayName;

switch (day)
{
    case 1:
        dayName = "Monday";
        break;
    case 2:
        dayName = "Tuesday";
        break;
    case 3:
        dayName = "Wednesday";
        break;
    case 4:
        dayName = "Thursday";
        break;
    case 5:
        dayName = "Friday";
        break;
    case 6:
        dayName = "Saturday";
        break;
    case 7:
        dayName = "Sunday";
        break;
    default:
        dayName = "Invalid day";
        break;
}

Console.WriteLine("Today is " + dayName);

Output:

Today is Wednesday

Explanation:

Here, the value of day is 3.
The switch statement compares day with each case.
When it matches case 3, it assigns "Wednesday" to dayName and exits the switch using break.
If day had an invalid value (like 8 or -1), the default case would assign "Invalid day" to dayName.

Important Points to Remember

Each case must end with a break (or a return, throw, or goto) to avoid fall-through.
The default case is optional but recommended for handling unexpected values.
case values must be constant expressions (like literals or constants).
In C# 7.0 and later, pattern matching with switch is also available for more complex comparisons.

Advantages of Using Switch-Case in C#

Improves readability compared to multiple if-else statements.
Organizes your code into clear, manageable sections.
Enhances performance slightly for many comparisons.
Makes maintenance and future updates easier.

Mastering Switch-Case in C#

The switch-case statement is an essential tool in C# that makes your code cleaner, more readable, and more efficient when dealing with multiple possible values.
By mastering it, you'll be able to write better-structured decision-making logic for your C# applications.

Practice writing different switch-case examples and try combining it with enums or strings to strengthen your C# programming skills!

Understanding the Switch-Case Statement in C# (With Full Explanation and Example)