Is it legal: String x = "Hello"; int y = 9; x += y; : Questions « Operators « SCJP

1. SCJP
2. Operators
3. Questions

A. Legal
B. Illegal

public class MainClass{
    public static void main(String[] argv){
        String x = "Hello"; int y = 9; x += y;
        System.out.println(x);
        System.out.println(y);
    }
}