try...catch

In this chapter you will learn:

  1. Exception Handling Fundamentals
  2. Exception handling with trying and catching
  3. Use a nested try block

Statements to handle exceptions

C# exception handling is managed via four keywords: try, catch, throw, and finally.

try {//j av a  2  s .  c o  m
    // block of code to monitor for errors
}
catch (ExcepType1 exOb) {
    // handler for ExcepType1 
}
catch (ExcepType2 exOb) {
    // handler for ExcepType2 
}
.
.
finally{

}

If no exception is thrown by a try block, no catch statements will be executed and program control resumes after the catch statement.

Exception handling with trying and catching

using System;/*from   ja  v  a  2  s  .  co m*/

class MainClass{
    
    
    public static void Main(){
        Console.WriteLine("Before catch");
        int Zero = 0;
        try {
            int j = 22 / Zero;
        } catch (Exception e) {
            Console.WriteLine("Exception " + e.Message);
        }
        
        Console.WriteLine("After catch");
    }
}

The code above generates the following result.

Use a nested try block

using System; /*from   j  a  v  a2 s.com*/
 
class MainClass { 
  public static void Main() { 
    int[] numer = { 4, 8, 16, 32, 64, 128, 256, 512 }; 
    int d = 0;
 
    try { // outer try 
      for(int i=0; i < 10; i++) { 
        try { // nested try 
          Console.WriteLine(numer[i] + " / " + 
                             numer[i] + " is " + 
                             numer[i]/d); 
        } 
        catch (DivideByZeroException) { 
          // catch the exception 
          Console.WriteLine("Can't divide by Zero!"); 
        } 
      } 
    }  
    catch (IndexOutOfRangeException) { 
      // catch the exception 
      Console.WriteLine("No matching element found."); 
      Console.WriteLine("Fatal error -- program terminated."); 
    } 
  } 
}

The code above generates the following result.

Next chapter...

What you will learn in the next chapter:

  1. Use multiple catch statements
  2. Use the 'catch all' catch statement
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