session4 : assesment on this and super keyword

[bik-on-git]

public class ThisKeyA {

String z = "hello";

void newTest()
{
    System.out.println(this.z);
}

@Override
public String toString() {
    return  z;
}

public static void main(String[] args) {
    ThisKeyA t1 = new ThisKeyA();
    t1.newTest();
}}

[nimadsherpa]

package keywords;

//abstract class
public abstract class Shape {

    String shapeName;
    final float pi = 3.14f;

    Shape(String shapeName){
        this.shapeName = shapeName;
    }

    // abstract method
    abstract float calculateArea();

}

package keywords;

public class Circle extends Shape{

    float radius;

    Circle(String name, float radius){
        super(name);                    //calling parent constructor with argument
        this.radius = radius;
    }

    float calculateArea() {
        return (pi*(radius*radius));}
}

package keywords;

public class Main {
    public static void main(String[] args) {
        float radius = 8.7f;
        float area; 
        Circle shape1 = new Circle("Circle", radius);
        area = shape1.calculateArea();
        System.out.println(shape1.shapeName + " area with radius " + radius + " is: " + area);
    }

}

// Sample output: Circle area with radius 8.7 is: 237.6666

[mwdorji]

public class Sample { String name; String email;

Sample(String name, String email){
    this.name = name;
    this.email = email;
}
void print() {
    System.out.println("Name: "+ name);
    System.out.println("Email: "+ email);
}

}

public class SampleInfo extends Sample { String Id;

SampleInfo( String name, String email, String Id){
    super(name, email);
    this.Id = Id;
}
void identity() {
    System.out.println("Id: "+ Id);
}
void print() {
    super.print();
System.out.println("Id: "+ Id);
}

}

public class Main { public static void main(String[] args) { SampleInfo S = new SampleInfo("Menda", "ex@takeo","80623"); System.out.println(S.name); System.out.println(S.email); S.identity(); S.print();

}

}

Output ex@takeo Id: 80623 Name: Menda Email: ex@takeo Id: 80623

[dhawasangbolama2]

//use of super and this keyword class World {

public void continents() {

    System.out.println("There are 7 contenents with 195 countries in the world.");
}

} class Continents extends World{

String Continent = "North America";

public void continents() {
    super.continents();
    System.out.println("There are so many countries in each contenent.");
    System.out.println("United States is in "+ this.Continent +".");

}

} public class Earth{

public static void main(String[] args) {
    World ourEarth = new Continents();
    ourEarth.continents();

}

}

OUTPUT

There are 7 contenents with 195 countries in the world. There are so many countries in each contenent. United States is in North America.

[gsajan21]

public class Test {

int number = 0;
String name = "Sajan Gurung";

void print(){
    System.out.println(number + " " + name);
}

Test (){
    System.out.println("This is the parent class constructor.");
}
Test (int a){
    this.number = a;
    System.out.println("Now the value of number is: " +  number);
}

void sum(int num){
    System.out.println(number + num);
}

}

public class TestDemo extends Test {

TestDemo(){
    super(100);
    System.out.println("This is child class constructor.");
}

void sum(int a){

    System.out.println(a+34687);
    super.sum(a); // super calls the sum method from the Test class which is parent class
}
public static void main(String[] args) {
    TestDemo t = new TestDemo();
    t.sum(100);
}

}