Error with initializing in JAVA

This is my code:


import java.text.DecimalFormat;
import javax.swing.JOptionPane;
import java.util.Random;

public class MathTutor

{

public static void main(String[]args)

{

int num1;
int num2;
int sum;
int answer;
int symbol;

String input;

DecimalFormat dfmt = new DecimalFormat("#0.00");

Random r = new Random();

num1 = r.nextInt(10)+ 1;
num2 = r.nextInt(10)+ 1;
symbol = r.nextInt(4)+ 1;

if (symbol == 1){
sum = num1 + num2;
}
if (symbol == 2){
sum = num1 - num2;
}
if (symbol == 3){
sum = num1*num2;
}
if (symbol == 4){
sum = num1/num2;
}

input = JOptionPane.showInputDialog(null, "What is the answer to the following question? \n" + num1 + symbol + num2 + " = ?");
answer = Integer.parseInt(input);

if (answer == sum){
JOptionPane.showMessageDialog(null, "Correct!");
}
else{
JOptionPane.showMessageDialog(null, "Wrong! The answer is: " + sum);
}

}





This is the error:


java:45: variable sum might not have been initialized
if (answer == sum){
^

 

just change 'int sum;' to 'int sum=0;'

since the only time you give sum a value is inside of an if statement, java assume the worst that none of your if statements are true, therefore will never be initiazlied

welcome to java

 

haha thanks