Why do I get an error "variable num1 might not have been initialized" when using try catch here? [duplicate]

When I try to use a try catch exception handler in my code, I'm getting the error message:

java: variable num1 might not have been initialized

The code seems to work when I initialize num1 as num1 = 0. Is there any technique to use try catch by just initializing int num1? Why do I get the error?

Code snippet:

import java.util.Scanner; public class Calculator { public static void main(String[] args) { int num1, num2, ans; String operator; Scanner scn1 = new Scanner(System.in); Scanner scn2 = new Scanner(System.in); //Getting first number try { System.out.print("Enter your first number : "); num1 = scn1.nextInt(); } catch(Exception e) { System.out.println("Enter an integer!"); } //Getting second number System.out.print("Enter the second number : "); num2 = scn1.nextInt(); //Getting operator System.out.print("Enter an operator(+, -, *, /) : "); operator = scn2.nextLine(); //test System.out.println("First number : " + num1); System.out.println("Second number : " + num2); System.out.println("Operator : " + operator);