How to Use Multiple Catch Clauses in C#?

Last Updated : 25 Jan, 2025

In C#, the main purpose of a catch block is to handle exceptions raised in the try block. A catch block is executed only when an exception occurs in the program. We can use multiple catch blocks with a single try block to handle different types of exceptions. Each catch block is designed to handle a specific type of exception.

Note: C# does not allow multiple catch blocks for the same exception type, because it will cause a compile-time error. The catch blocks are evaluated in the order they appear. If an exception matches the first catch block, the remaining catch blocks are ignored.

Syntax of try-catch with Multiple Catch Clauses:

try

{ // Code that may throw an exception }

catch (ExceptionType1 ex)

{ // Handle ExceptionType1 }

catch (ExceptionType2 ex)

{ // Handle ExceptionType2 }

// Add more catch blocks as needed

finally

{ // Code that executes regardless of exceptions (optional) }

Example 1: Handling DivideByZeroException and IndexOutOfRangeException

In this example, the try block generates two types of exceptions:

DivideByZeroException: When trying to divide a number by zero.
IndexOutOfRangeException: When accessing an array with an invalid index.

Each exception is handled by a specific catch block.

// C# program to illustrate multiple catch blocks using System;  class Geeks {     static void Main()     {         // Arrays for demonstration         int[] num = { 8, 17,5 };         int[] divisors = { 2, 0, 4 };          // Iterate through numbers and divisors         for (int i = 0; i < num.Length; i++)         {             try             {                 // Display current number and divisor                 Console.WriteLine($"Number: {num[i]}");                 Console.WriteLine($"Divisor: {divisors[i]}");                  // Perform division                 Console.WriteLine($"Quotient: {num[i] / divisors[i]}");             }             catch (DivideByZeroException)             {                 // Handle division by zero                 Console.WriteLine("Error: Division by zero is not allowed.");             }             catch (IndexOutOfRangeException)             {                 // Handle invalid array index                 Console.WriteLine("Error: Index is out of range.");             }             finally             {                 // Execute cleanup code (if needed)                 Console.WriteLine("Operation completed.\n");             }         }     } }

Output

Number: 8 Divisor: 2 Quotient: 4 Operation completed.  Number: 17 Divisor: 0 Error: Division by zero is not allowed. Operation completed.  Number: 5 Divisor: 4 Quotient: 1 Operation completed.

Example 2: Handling Multiple Exception Types in Parsing

This example demonstrates using multiple catch blocks to handle exceptions such as FormatException (invalid input format) and OverflowException (data out of range).

// C# program to demonstrate multiple catch clauses using System;  class Geeks {     static void Main()     {         try         {             // Trying to parse invalid input             byte data = byte.Parse("a");             Console.WriteLine($"Parsed Data: {data}");         }         catch (FormatException)         {             // Handle invalid input format             Console.WriteLine("Error: The entered value is not a valid number.");         }         catch (OverflowException)         {             // Handle data out of range for a byte             Console.WriteLine               ("Error: The entered value is outside the valid range for a byte.");         }         catch (Exception ex)         {             // General exception handling (fallback)             Console.WriteLine($"Unexpected error: {ex.Message}");         }         finally         {             // Execute code regardless of exceptions             Console.WriteLine("Operation completed.");         }     } }

Output

Error: The entered value is not a valid number. Operation completed.

Important Points:

The catch blocks are evaluated in the order they appear. Ensure more specific exceptions (e.g., DivideByZeroException) appear before more general ones (e.g., Exception).
Use a finally block for cleanup operations like closing resources, which should run regardless of whether an exception is raised.
Always use a general catch (Exception ex) block at the end to handle any unexpected exceptions.

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How to Use Multiple Catch Clauses in C#?

Example 1: Handling DivideByZeroException and IndexOutOfRangeException

Example 2: Handling Multiple Exception Types in Parsing

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