Why is this code not valid?

Question

public class Sololearn {
int i = 7;
public static void main(String[] args) {
i++;
}
}

Answer 1

to use i in main you have to make it static.

public class Sololearn {
static int i = 7;
public static void main(String[] args) {
i++;
}
}

Answer 2

or declare i locally within main or method.

public class Sololearn {
public static void main(String[] args) {
int i=7;
i++;
}
}

Answer 3

Nice!