What are the different types of conditional statements supported by C#?

Conditional statements in C# allow programs to execute different code blocks based on specified conditions. These statements evaluate boolean expressions and direct program flow accordingly, enabling dynamic decision-making in applications.

Types of Conditional Statements

Syntax

Following is the basic syntax for different conditional statements −

// if statement
if (condition) {
   // statements
}

// if...else statement
if (condition) {
   // statements if true
} else {
   // statements if false
}

// switch statement
switch (variable) {
   case value1:
      // statements
      break;
   case value2:
      // statements
      break;
   default:
      // default statements
      break;
}

Using if Statement

Example

using System;

class Program {
   public static void Main() {
      int number = 10;
      
      if (number > 5) {
         Console.WriteLine("Number is greater than 5");
      }
      
      if (number % 2 == 0) {
         Console.WriteLine("Number is even");
      }
   }
}

The output of the above code is −

Number is greater than 5
Number is even

Using if...else Statement

Example

using System;

class Program {
   public static void Main() {
      int score = 75;
      
      if (score >= 60) {
         Console.WriteLine("Pass");
      } else {
         Console.WriteLine("Fail");
      }
      
      // Multiple conditions with else if
      if (score >= 90) {
         Console.WriteLine("Grade: A");
      } else if (score >= 80) {
         Console.WriteLine("Grade: B");
      } else if (score >= 70) {
         Console.WriteLine("Grade: C");
      } else {
         Console.WriteLine("Grade: D");
      }
   }
}

The output of the above code is −

Pass
Grade: C

Using switch Statement

Example

using System;

class Program {
   public static void Main() {
      char grade = 'B';
      
      switch (grade) {
         case 'A':
            Console.WriteLine("Excellent!");
            break;
         case 'B':
            Console.WriteLine("Good job!");
            break;
         case 'C':
            Console.WriteLine("Well done");
            break;
         case 'D':
            Console.WriteLine("You passed");
            break;
         case 'F':
            Console.WriteLine("Better try again");
            break;
         default:
            Console.WriteLine("Invalid grade");
            break;
      }
   }
}

The output of the above code is −

Good job!

Using Nested switch Statement

Example

using System;

class Program {
   public static void Main() {
      int a = 100;
      int b = 200;
      
      switch (a) {
         case 100:
            Console.WriteLine("This is part of outer switch");
            
            switch (b) {
               case 200:
                  Console.WriteLine("This is part of inner switch");
                  break;
               case 300:
                  Console.WriteLine("Inner case 300");
                  break;
               default:
                  Console.WriteLine("Inner default case");
                  break;
            }
            break;
         case 200:
            Console.WriteLine("Outer case 200");
            break;
         default:
            Console.WriteLine("Outer default case");
            break;
      }
   }
}

The output of the above code is −

This is part of outer switch
This is part of inner switch

Comparison of Conditional Statements

Conclusion

C# provides several conditional statements including if, if...else, nested if, switch, and nested switch statements. Choose if statements for boolean conditions and switch statements when testing a single variable against multiple discrete values. Proper use of these statements creates clean, readable, and efficient code flow control.