Throwable toString() method in Java with Examples

The toString() method of the java.lang.Throwable class is used to return a string representation of an exception or error. It is commonly used while printing exceptions to understand what went wrong in a program.

Below example demonstrates how Throwable.toString() provides a concise description of an exception.

java.lang.ArithmeticException: / by zero

Explanation :

• code deliberately causes an ArithmeticException by dividing 10 by 0.
• exception is caught in the catch block.
• e.toString() returns a string containing the exception’s class name and message.
• output shows: java.lang.ArithmeticException: / by zero.

Syntax

public String toString()

• Parameters: This method does not take any parameters.
• Return Value: Returns a String representing the Throwable.

Example: This code demonstrates how to use the toString() method of the Throwable class in Java to get a readable description of an exception.

java.lang.NullPointerException

Explanation:

• A NullPointerException is explicitly thrown using throw new NullPointerException().
• The exception is caught in the catch block as a generic Exception.
• e.toString() is called to get a string representation of the exception.
• Since no custom message is provided, it outputs the class name: java.lang.NullPointerExceptio

Related Topics:

• Throwable class in Java
• getMessage()
• Exception Handling in Java