Function Demo Pass By Value

#1

public class FunctionDemo4 {

public static int vaL = 20;

public static void main(String[] args) {

    //part 1: Normal Call

    System.out.println("Part 1: Normal Call");

    System.out.println("hello");
    //function call
    addition();
    System.out.println("by");

    //Part 2:Function with Parameters
    System.out.println("part 2 : Function with Parameters");

    additionParams(10, 20);
    additionParams(20, 30);


    //Part 3:Function Return Value
    System.out.println("Part 3: Function Return Value:");

    int sum = additionReturn(30, 40);
    System.out.println(sum);


    //Part 4: Variable Scope
    System.out.println("Part 4: Variable Scope");
    int one = 10;
    int two = 20;
    int res = DemoScopes(one, two);
    System.out.println(res);


    //Part 5:Global Scope
    System.out.println("Part 5: Global Scope");
    System.out.println(vaL);
    int val = 200;
    System.out.println(val);
    System.out.println(FunctionDemo4.vaL);  //class name
    int ans = DemoGlobalScopes(one);
    System.out.println(ans);


    // Part 6: Block Scope
    System.out.println("Part 6 : Block Scope");

    if (one < two) {
        int three = 30;
        System.out.println(three);


    }
    // Part 7: Pass by Value

    System.out.println("Part 7: Pass by Value");
    System.out.println(one + " ," + two);
    Swap(one, two);
    System.out.println(one + " ," + two);

}


    public static int Swap ( int one, int two) {
        System.out.println(one + " ," + two);

        int temp = one;
        one = two;
        two = temp;
        System.out.println(one + " ," + two);

    }


    public static int DemoGlobalScopes ( int one) {
        int sum = one + vaL;
        return sum;
    }
    public static int DemoScopes ( int one, int another){
        int sum = one + another;
        return sum;
    }

    public static int additionReturn ( int a, int b){
        int sum = a + b;
        return sum;

    }

    public static void additionParams ( int a, int b){
        int sum = a + b;
        System.out.println(sum);
    }

    //new Function definition
    public static void addition () {
        int a = 5;
        int b = 10;
        int c = a + b;
        System.out.println(c);
    }
}

pls check me error