# Simple Java Programs for beginners  static final int p = 1000;
static final int m = 9;

public static void main (String [] args) {
System.out.println (“Simple addition. This is my first experiment in java”);
int Addition = p + m ;
System.out.println (“The answer of of “+p+ ” and” +m+
}
}

Pythagoras public class Pythagoras
{

public static void main (String [] args){

int a = 3;
int b = 4;

double power = Math.pow (a,2) + Math.pow (b,2);

double h = Math.sqrt(power);

System.out.println (“The Hypotenuse of a right angled triangle of sides 3cm and 4cm =”+h+” cm”);

}
}

import java.util.*;

{
public static void main(String[] args)
{
System.out.println( “This simple program adds six numbers using the nextInt” );

System.out.println( “Please, write down five numbers:” );

int n1, n2, n3, n4, n5, n6;

System.out.println( “The sum of those three numbers is: ” + (n1 + n2 + n3+ n4 + n5 +n6) );
}
}

Pythagoras (using Scanner Class)

import java.util.*;
import java.io.*;

public class PythagorasInput
{

public static void main (String [] args){

System.out.println( “This simple program will calculate the Hypotenuse of a triangle: “);

System.out.println( “Please enter side a of the triangle: “);

System.out.println( “Please enter side b of the triangle: “);

double power = Math.pow (a,2) + Math.pow (b,2);

double h = Math.sqrt (power);

System.out.println (“The Hypotenuse of a right angled triangle of sides “+a+” and “+b+ ” cm is ” +h+ ” cm”);

}
}

Case Switch

import java.util.*;

class Seasons
{

public static void main (String[] args){

Scanner sc= new Scanner(System.in);

int month = 12;

System.out.println( “This program allows the user to enter the season : “);

System.out.println( “Enter number of month: “);
month = sc.nextInt();

switch (month) {
case 12:
case 1:
case 2: System.out.println(“Winter”);break;
case 3:
case 4:
case 5: System.out.println(“Spring”);break;
case 6:
case 7:
case 8: System.out.println(“Summer”);break;
case 9:
case 10:
case 11: System.out.println(“Autumn”);break;
default: System.out.println(“Invalid month.”);break;
}

}
}

Populating 200 random numbers; finding average and numbers above the average and below the average

{

static int randomInt (int min, int max)

{

return min + (int) (Math.random()*(max-min+1));

}

public static void main (String[] args)

{ int arr[] = new int;

int sum=0; int above=0; int below =0;

float aver;

for (int k=0 ; k<=199; k++)

{ arr[k] = randomInt(0,100);

System.out.print(arr[k]+”\t”);

sum = sum + arr[k];

}

aver = sum/200;

System.out.println(“The average value is: “+aver+”\n”);

for (int k=0 ; k<=199; k++)

{ if (arr[k] < aver)

below++;

if (arr[k] > aver)

above++;

}

System.out.println(“Number of numbers above: “+above);

System.out.println(“Number of numbers below: “+below);

System.out.println();

System.out.println();

}

}

Generate  random numbers without repetition

class RandNoRepetition

{

public static void main (String[] args)

{ int myArr[] = new int;

int temp;

boolean found;

System.out.println (“Task: Generate 20 random numbers within 100-119 WITHOUT repetition”);

System.out.println (“Random number generation”);

for (int i=0; i<20;i++)  // 20 numbers required

{ do

{   temp = (int)(Math.round(100 + 20*Math.random()));

found = false;

for (int j=0;j<i; j++)

if (temp == myArr[j])

found = true;

}

while (found);

myArr[i] = temp;

System.out.println (“Random Number always >=100 generated: ” + myArr[i]);

}

}

}

Money conversion (Using JOptionPane)

import javax.swing.*;

import java.io.*;

public class Euroconverter  {

static float factor = (float)0.429;

public static void main(String args[])  {

Integer num;

Character c;

Float Inputamount;

String str = JOptionPane.showInputDialog

(“Please Enter 1 for Euro-to-LM conversion or 2 for Lm-to-Euro Conversion “);

num= new Integer(Integer.parseInt(str));

if (num==2)         {

String ammont = JOptionPane.showInputDialog (“Enter amount in Lm to convert “);

Inputamount= new Float (Float.parseFloat (ammont));

Float AmountinEuros = Inputamount/factor;

JOptionPane.showMessageDialog (null, “This amount is equal to ” +AmountinEuros + ” Euros”);

}

else{

String tieniammont = JOptionPane.showInputDialog

(“Enter amount in Euros to convert “);

Inputamount= new Float (Float.parseFloat (tieniammont));

float AmountinLM = Inputamount*factor;

JOptionPane.showMessageDialog (null, “This amount is equal to ” +AmountinLM + ” LM”);

}

JOptionPane.showMessageDialog (null, “Thank you for using our Euro converter ” );

System.exit(0);

}

}

Number Guessing game

// Number guessing game created by Omar Seguna

import java.util.*;

public class Numberguessinggame // The user is asked to guess the number and has 6 tries

{

static int randomnumber(int min, int max)

{

return (int)(Math.random() * max + 1);

}

public static void main (String[] args) // main

{

Scanner keyboard;

keyboard = new Scanner(System.in);

int a;

int i; //list of all variables

String b;

do {

int x= randomnumber (1,100);

System.out.println( “I thought of a number from 1 to 100.  Please try to guess the number : “);

for (i=1;i<60;i++) //print 60 wonderful stars

System.out.print(“*”);

System.out.println(” “);

//count must be initialised each time that the user starts a new game

int count = 1;

boolean correct = false;

//count++; count should be incremented with each try not with each game

do {  // will ask you the number unless smaller than 100

System.out.println( “Please enter the number from 1 to 100: “);

a = keyboard.nextInt();

} while (a >100);

if (a==x){

correct = true;

System.out.println (“You are a genius”); //if correct answer

} else if (a < x) {

//only check whether its less

System.out.print(“Try a bigger number. “);

count++;

} else if (a > x)  {

//only check whether its high

System.out.print(“Try a smaller number. “);

count++;

}

} while (count<=6 && correct == false);

System.out.println (“The number was ” +x ); //will print the random number

System.out.println (“Do you want to play again? [y/n]”);

b = keyboard.next();

}  while (b.equals (“y”));

}  // end of main

} // end of class