what is object in java code example
Example 1: java create new object
Car mycar = new Car();
Example 2: java class
public class Lightsaber {
// properties
private boolean isOn;
private Color color;
// constructor
public Lightsaber(Color color) {
this.isOn = false;
this.color = color;
}
// getters
public Color getColor() {
return color;
}
public boolean getOnStatus() {
return isOn;
}
// setters
public void turnOn() {
isOn = true;
}
public void turnOff() {
isOn = false;
}
}
// Implementation in main method:
public class test {
public static void main(String[] args) {
Lightsaber yoda = new Lightsaber(green);
yoda.turnOn();
}
}
Example 3: java class
// Example : TestClass (Can be predefined or user-defined)
public class TestClass {
// properties
private int id = 111;
// constructor
public TestClass(){
super();
}
// method
public void test(){
// some code here
}
}
Example 4: using class in java
class Number {
int number;
// square numbers
public boolean isSquare(){
double squareRoot = Math.sqrt(number);
if(squareRoot == Math.floor(squareRoot))
{
return true;
} else {
return false;
}
}
// triangular numbers
public boolean isTriangular(){
int x = 1;
int triangularNumber = 1;
while(triangularNumber < number){
x++;
triangularNumber = triangularNumber + x;
}
if(triangularNumber == number){
return true;
} else {
return false;
}
}
}
// testing
Number myNumber = new Number();
myNumber.number = 16;
System.out.println(myNumber.isSquare());
Example 5: using class in java
public class HelloWorld {
public static void main(String[] args) {
class Number{
int number;
public boolean isPos(){
if(number > 0){
return true;
} else {
return false;
}
}
}
Number myNumber = new Number();
myNumber.number = 7;
if(myNumber.isPos()){
System.out.println(myNumber.number + " is positive!!!");
} else {
System.out.println(myNumber.number + " is not positive!!!");
}
}
}
Example 6: object in java
Objects: came from class, we can create multiple objects from a class
ArrayList<> list = new ArrayList<>();
Class refName OBJECT
each object has its own copy of instance variable
· declared outside the blocks or methods
Object: Instance of the class. We can store different data's to objects
Object Creation: with new keyword.
ClassName obj = new ExistingConstructor;