Question

I am getting the following error in my Java program:

Java variables not initialized error… error : variable nam and r not
initialized location class child

But nan and r already initialized, yet I am still getting the same error.

public class cla {
    int rn;
    String name;

    void get(String a, int x) {
        name = a;
        rn = x;
    }

    void display() {
        System.out.println("student name: " + name + "roll no.:" + rn);
    }
}

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class child {
    public static void main(String args[]) throws IOException {
        String nam;
        int r;
        BufferedReader bReader = new BufferedReader(new InputStreamReader(
            System.in));
        try {
            System.out.println("enter name and roll no.");
            nam = bReader.readLine();
            r = Integer.parseInt(bReader.readLine());

        } catch (Exception e) {
        }
        cla c = new cla();
        c.get(nam, r);
        c.display();
    }

Answer 1

Local variables don’t get default values, you should initialize them before you use them , initialize nam and r with default values inside your main and you will be fine.

public static void main(String args[]) throws IOException{
String nam=null;
int r=0;

BTW, consider naming your class’s and variables something meaningful.