GCSE Link: 2.14 (Errors)

Example 1 shows some example C# code to add 5 to a given number.

Example 1
int num = Convert.ToInt32(Console.ReadLine());
Console.WriteLine(num + 5);

This works fine when the user inputs a number like 7, but if the user enters something like abc, the program will crash:

Unhandled exception. System.FormatException: The input string 'abc' was not in a correct format.
   at System.Number.ThrowFormatException[TChar](ReadOnlySpan`1 value)
   at System.Convert.ToInt32(String value)
   at Program.Main()
Command terminated by signal 6

So, we need to handle this exception. We use the try...catch syntax.

Example 2 shows some example C# code to add 5 to a given number with exception handling.

Example 2
try {
  int num = Convert.ToInt32(Console.ReadLine());
  Console.WriteLine(num + 5);
} catch (Exception e) {
  Console.WriteLine("Error: " + e);
  // Do anything here
}

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Can you think of any other common scenarios where exceptions can occur?

Index out of range when indexing an array; Dividing by zero; Integer overflows

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