Tasks:

1) Java variable names.

Make the program work (var starts with 1, $, % etc). Update given code so as to be able to compile it:

public class JavaVariableNames {
    public static void main(String[] args) {
        int 2morrow = 0;
        int $money = 10;
        int %hundred = 100;
        int !back = 1000;
        int _underscore = 10000;
        int #sharp = 100000;
        int *star = 1000000;
        int BADEXAMPLEOFVARNAME = 1000000;
    }
}

2) Copied names.

Make the program work (vars have the same names). Update given code so as to be able to compile it:

public class CopiedNames {
    public static void main(String[] args) {
        int variable = 0;
        int variable = 2000;
        int value = 1000;
        int variable = 4000;
        int value2 = 3000;
        int variables = 5000;
        variables = 7000;
        int value = 90000;
        int int = 100000;
        int my integer = 1000000;
        int my+var = 1234567;
        int my__-__integer = 1234567;
    }
}

3) Naming conventions.

Update given code so that it is corresponding to java name conventions, notice the constants with the keyword final, following the case of variables (if the variable in example is in snake case this pattern should be followed):

public class NamingConvention {
    public static void main(String[] args) {
         int _variable = 10;
         int variable_One = 1;
         int variableTwo = 2;
         int variable_three = 3;
         final int VARIABLEFOUR = 4;
         final int VARIABLEfIVE = 5;
         int VariableSix = 6;
         int variableseven = 7;
         int VariableEight = 8;
    }
}

4) Advanced naming convention.

(After advanced reading about java naming conventions ) In the given code snippet make the program correspond to java code conventions (method, class, field names...):

public class advancedNamingConvention {
    private static final int adult_age = 18;

    private int AGE;
    private int phoneNumber;

    void CAllToFriend() {
        //some code
    }

    void callByNumber(int Number) {
        //some code
    }
}