java.lang.NumberFormatException

In Java, a NumberFormatException is an exception that is thrown when you try to convert a string to a numeric type (such as int, double, float, etc.) but the string's format is not compatible with the expected format for that numeric type. This typically occurs when you're using parsing methods like Integer.parseInt(), Double.parseDouble(), or Float.parseFloat().

For example, if you have the following code:

package Tutorial_00;

public class Blog02 {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		String strvalue = "abc";
		int numbervalue = Integer.parseInt(strvalue);
				  
		}

	}

Since the string "abc" cannot be converted to an integer, the parseInt() method will throw a NumberFormatException. To handle this exception and prevent your program from crashing, you can use a try-catch block like this:

package Tutorial_00;

public class Blog02 {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		String strvalue = "abc";
		try {
		    int numbervalue = Integer.parseInt(strvalue);
		    // rest of the code if conversion is successful
		} catch (NumberFormatException e) {
		    System.out.println("Error: " + e.getMessage());
		    // handle the exception, maybe provide a default value or ask the user for valid input
		}  
		}

	}
	

This will catch the NumberFormatException if it occurs during the parsing, and you can implement appropriate error handling within the catch block. It's a good practice to always validate and sanitize user input before attempting to parse it, to avoid such exceptions and ensure a smoother user experience.