How to use strings in switch statement in C#

A switch statement allows a variable to be tested for equality against a list of values. Each value is called a case, and the variable being switched on is checked for each switch case. In C#, you can use strings directly in switch statements, making it convenient to handle text-based conditions.

Syntax

Following is the syntax for using strings in a switch statement −

switch (stringVariable) {
   case "value1":
      // code block
      break;
   case "value2":
      // code block
      break;
   default:
      // default code block
      break;
}

Key Rules

• String comparisons in switch statements are case-sensitive.

• Each case must end with a break statement to prevent fall-through.

• The default case is optional and executes when no other case matches.

• String literals must be compile-time constants in case labels.

Using Strings in Switch Statement

Example 1: Grade Evaluation

using System;

public class Demo {
   public static void Main(String[] args) {
      string grades = "A1";
      switch (grades) {
         case "A1":
            Console.WriteLine("Very good!");
            break;
         case "A2":
            Console.WriteLine("Good!");
            break;
         case "B1":
            Console.WriteLine("Satisfactory!");
            break;
         default:
            Console.WriteLine("Invalid!");
            break;
      }
      Console.WriteLine("Grade = " + grades);
   }
}

The output of the above code is −

Very good!
Grade = A1

Example 2: Day of Week Processing

using System;

public class WeekdayDemo {
   public static void Main(String[] args) {
      string day = "Monday";
      string dayType;
      
      switch (day) {
         case "Monday":
         case "Tuesday":
         case "Wednesday":
         case "Thursday":
         case "Friday":
            dayType = "Weekday";
            break;
         case "Saturday":
         case "Sunday":
            dayType = "Weekend";
            break;
         default:
            dayType = "Invalid day";
            break;
      }
      
      Console.WriteLine(day + " is a " + dayType);
   }
}

The output of the above code is −

Monday is a Weekday

Case Sensitivity in String Switch

Example 3: Demonstrating Case Sensitivity

using System;

public class CaseSensitivityDemo {
   public static void Main(String[] args) {
      string color = "red";
      
      switch (color) {
         case "Red":
            Console.WriteLine("Capital R - Red");
            break;
         case "red":
            Console.WriteLine("Lowercase - red");
            break;
         case "GREEN":
            Console.WriteLine("Uppercase - GREEN");
            break;
         default:
            Console.WriteLine("Color not found");
            break;
      }
      
      // Test with different casing
      string anotherColor = "Red";
      switch (anotherColor) {
         case "Red":
            Console.WriteLine("Found: " + anotherColor);
            break;
         default:
            Console.WriteLine("Not found: " + anotherColor);
            break;
      }
   }
}

The output of the above code is −

Lowercase - red
Found: Red

Conclusion

String switch statements in C# provide a clean and readable way to handle multiple string comparisons. Remember that string comparisons are case-sensitive, and each case must include a break statement to prevent fall-through behavior.