FormatException

System

Summary

Represents errors that occur when the format of a string or other input data is not valid.

Syntax

public class FormatException : Exception

Namespace: System
Assembly: System.Runtime.dll

Remarks

The FormatException class is used to signal that an input string does not conform to the expected format. For example, this exception can be thrown when parsing a string to a numeric type (like int.Parse or double.Parse) and the string contains invalid characters or an incorrect structure.

This exception is typically thrown by methods that convert a string representation of a value to its equivalent numeric, date and time, or other non-string type.

The FormatException class inherits from the Exception class. It includes standard exception properties such as Message, InnerException, and StackTrace.

Exceptions

Example

The following code example demonstrates how to catch a FormatException when attempting to parse an invalid string to an integer.

using System;

public class Example
{
    public static void Main(string[] args)
    {
        string invalidString = "abc";
        int number;

        try
        {
            number = int.Parse(invalidString);
            Console.WriteLine($"Parsed number: {number}");
        }
        catch (FormatException e)
        {
            Console.WriteLine($"Error: {e.Message}");
            Console.WriteLine("The input string is not a valid integer format.");
        }
        catch (OverflowException e)
        {
            Console.WriteLine($"Error: {e.Message}");
            Console.WriteLine("The number is too large or too small for an Int32.");
        }
    }
}

See Also