Java Basic Logic Building Programs and examples

JAVA Basic concepts and examples

JAVA Basic concepts

JAVA first program ‘Hello World’

Java Basic Logic Building Programs | Hello World is the simplest program in every programming language. You should start with this program if you are new in programming.

public class HelloWorld {

public static void main(String[] args) {
HelloWorld helloWorld = new HelloWorld();
helloWorld.printWord(); //method call

}
public void printWord(){ /* method definition */
System.out.println("Hello World");
}
}

 

Program to find factorial using JAVA

Factorial of a positive number n is given by:

factorial of n (n!) = 1 * 2 * 3 * 4 * ... * n

class Factorial{
    public static void main(String args[]){
        Factorial obj = new Factorial();
//Method call
        obj.findFact();

    }
    //Method definition
    public void findFact(){
        int i;
        int num = 5;
        int fact = 1;
        for (i=1; i<=num; i++){
            fact = fact * i;
        }
        System.out.println("Factorial of "+ num + " is: "+ fact);
    }
}

 

When you run this program, output will be:

Factorial of 10 = 120

Program to perform normal mathematics operation in JAVA

public class MathOperation {
    public static void main(String[] args) {
        MathOperation mathOperation = new MathOperation();
        mathOperation.sumTotal();
        mathOperation.multi();
        mathOperation.division();
        mathOperation.difference();
    }

    public void sumTotal(){
        int a = 80;
        int b = 50;
        int sum = a + b;
        System.out.println("Sum is"+ sum);
    }
    public void multi(){
        int a = 80;
        int b = 50;
        int mul = a * b;
        System.out.println("multiplication" + mul);
    }
    public void difference(){
        int a = 80;
        int b = 50;
        int min = a - b;
        int div = a / b;
        System.out.println("Difference" + min);
    }
    public void division(){
        int a = 80;
        int b = 50;
        int div = a / b;
        System.out.println("Division" + div);
    }
}

 

If-else condition in JAVA

public class IfElseConcept {

    public static void main(String[] args) {
        int a = 100;
        int b = 20;

        if(b>a) {
            System.out.println("b is greater than a");
        }else {
            System.out.println("a is greater than b");

        }
//Comparison Operators
// < > <= >= == !=

        int c = 40;
        int d = 40;
        if(c==d) {
            System.out.println("C and D are Equal");
        }else {
            System.out.println("C and D are not equal");
        }
//WAP to find out the highest number
        int a1 = 10000;
        int b1 = 2000;
        int c1 = 300;

//Nested If-Else
        if(a1>b1 & a1 > c1) {//false & false = false
            System.out.println("a1 is greater");
        }else if(b1>c1) {
            System.out.println("b1 is greater");
        }else {
            System.out.println("c1 Is greater");
        }

    }

}

 

 

To print the Star pattern Program in JAVA

public class PrintStar {
    public static void main(String[] args){
        PrintStar obj = new PrintStar();
        obj.Star();
        obj.revStar();
    }
    public void Star(){
        int i;
        int j;
        for(i=1; i<=6; i++) {
            for(j=1; j<i; j++) {
                System.out.print("*");
            } System.out.println("");
        }
        System.out.println(""); //To separate two modules of star
    }
    public void revStar(){
        for(int i = 5; i>=1; i--)
        {
            for(int j = 1; j<=i; j++)
            {
                System.out.print("*"); }
            System.out.println(); }
    }
} //End of class

 

 

Java Basic Logic Building Programs and examples

Output:
*
**
***
****
*****

*****
****
***
**
*

 

Program for Basic Constructor Example

public class PersonDetails {

    //Defining Variables
    String first_name;
    String last_name;
    String Address;
    String email;
    int contact;
    //To print Data
    public void printData(){
        System.out.println("Name of person is: "+ first_name +" "+ last_name );
        System.out.println("Address: "+ Address);
        System.out.println("Email ID "+ email);
        System.out.println("Mobile Number: "+ contact);
    }

//Building Parameterized Constructor

    public PersonDetails( String fname, String lname, String add, String mail, int con){
        first_name = fname;
        last_name = lname;
        Address = add;
        email = mail;
        contact = con;
    }

//Main Method

    public static void main(String[] args) {
//Passing parameter values
        PersonDetails personDetails = new PersonDetails("Santosh", "Adhikari", "Kathmandu Nepal", "[email protected]",123456789);
        personDetails.printData();

    }
}

 

OUTPUT:
Name of person is: Santosh Adhikari
Address: Kathmandu Nepal
Email ID [email protected]
Mobile Number: 123456789

Example of Method overloading

package PolyMorphism;

public class PolyMorphismDemo {
    public void sum(int a, int b){
        int total = a + b;
        System.out.println(total);
    }
    public void sum(float a, float b){
        float total = a + b;
        System.out.println(total);
    }

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

    public static void main(String[] args) {
        PolyMorphismDemo polyMorphismDemo = new PolyMorphismDemo();
        polyMorphismDemo.sum(10,20, 21);
    }
}

 

 

Program to insert array element on desired array location
package RandomPractice;

import java.util.Scanner;

public class InsertElementInArray {
    public void insertArray(){
        try {
            int[] arr = new int[5];
            System.out.println("Enter the element of array");
            Scanner scanner = new Scanner(System.in);

            for (int i = 0; i < arr.length; i++) {
                arr[i] = scanner.nextInt();
            }
            System.out.println("Printing elements before insert");

            for (int i : arr) {
                System.out.println(i);
            }

            System.out.println("Enter the location for storing element value");
            int location = scanner.nextInt();

            System.out.println("Enter the value that which ou want to insert");
            int value = scanner.nextInt();

            for (int i = arr.length - 1; i > location; i--) {
                arr[i] = arr[i - 1];
            }
            arr[location] = value;

            for (int i : arr) {
                System.out.println(i);
            }
        }catch (ArrayIndexOutOfBoundsException e){
            System.out.println("maximum array size is 5 i.e 0 to 4");
        }
    }


    public static void main(String[] args) {
        InsertElementInArray insertElementInArray = new InsertElementInArray();
        insertElementInArray.insertArray();
    }

}

 

NOTE: We won’t let you copy these codes, You have to write these codes yourself. Otherwise, our effort will be not effective 

 

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