how to create class in java code example
Example 1: classes in java
// this might help you understand how classes work
public class MathTest {
public static void main(String[] args) {
class MathAdd {
int num1;
int num2;
public int addNumbers() {
int addThemUp = num1 + num2;
return addThemUp;
}
}
MathAdd addition = new MathAdd(); // create a new instance of the class
// you can access variables from the class
addition.num1 = 10;
addition.num2 = 20;
// and use the method from the class to add them up
System.out.println(addition.addNumbers());
}
}
Example 2: using class in java
public class HelloWorld {
public static void main(String[] args) {
// how to use class in java
class User{
int score;
}
User dave = new User();
dave.score = 20;
System.out.println(dave.score);
}
}
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: class in java
Class is a blueprint or template which
you can create as many objects as you
like. Object is a member or instance
of a class.
Class is declared using class keyword,
Object is created through
new keyword mainly. A class is a template
for objects. A class defines
object properties including a valid range
of values, and a default value.
A class also describes object behavior.