Exception Handling

Exception In Java

An error will occur when there is wrong user input, e.g., user-entered alphabet where a number is needed. You can see the long message. You can use try-catch to catch the error and perform your task when the exception occurs.

Syntax Of Try Catch

try {
  //  Code to try
}
catch(Exception e) {
  //  Code to Handle Error
}

Basic Java Program

import java.util.Scanner;
public class Main {
    public static void main(String[] args) {
      Scanner sc = new Scanner(System.in);

        System.out.println("Enter your birth year: ");
        int birthyear = sc.nextInt();
        int age = 2022 - birthyear;
        System.out.println("Your age is "+age);

    }

}

Show Output

In this program, an error will be shown if you enter alphabets instead of a number.

Same Program With Try Catch

import java.util.Scanner;
public class Main {
    public static void main(String[] args) {
      Scanner sc = new Scanner(System.in);

        System.out.println("Enter your birth year: ");
        try{
            int birthyear = sc.nextInt();
            int age = 2022 - birthyear;
            System.out.println("Your age is "+age);
        }catch (Exception ex){
            System.out.println("Error make sure input is correct.");
        }
    }
}

Show Output

Finally

It can execute code regardless of any result in a try-catch.

import java.util.Scanner;
public class Main {
    public static void main(String[] args) {
      Scanner sc = new Scanner(System.in);

        System.out.println("Enter your birth year: ");
        try{
            int birthyear = sc.nextInt();
            int age = 2022 - birthyear;
            System.out.println("Your age is "+age);
        }catch (Exception ex){
            System.out.println("Error make sure input is correct.");
        }finally{
            System.out.println("This is finally. ");
        }

    }
}

Show Output