Looping Dan contoh dalam aplikasi java

                                         LOOPING (PERULANGAN)

~Looping jika jabarkan lagi berasal dari kata Loop, artinya lingkaran. Lingkaran memiliki ciri melingkar yang memiliki arti kembali lagi, mengulang.
~Looping artinya Perulangan, dari arti ini kita dapat mengamil point awal yaitu looping adalah perulangan. Perulangan seperti apa?
Jadi,Looping adalah Suatu intruksi untuk membentuk aksi kerja secara berulang pada blok yang sama, dimana didalam blok yang akan diulang ada terdapat statement atau pernyataan.

Contoh looping dalam pengaplikasian Java
1.      Buatlah program untuk menerima input bilangan bulat positif n dan menampilkan n bilangan bulat positif pertama yang habis dibagi 3 tetapi tidak habis dibagi 2.
Contoh :
Input = 5
Output = 3 9 15 21 27

Jawab :
import java.util.Scanner;

/**
 * @author user
 */
public class s {

 /**
  * @param args the command line arguments
  */
 public static void main(String[] args) {
  Scanner input = new Scanner(System.in);
  int n;

  System.out.print("n = ");
  n = input.nextInt();

  for (int i = 1; i <= n; i++) {
   int x = (i * 6) - 3;
   System.out.print(x + " ");
  }
 }
}






2.      Buatlah program untuk membaca 7 data bilangan bulat psitif dari keyboard. Kemudian menghitung nilai terbesar kedua dari data tersebut dan menampilkan di layar monitor.
Contoh :     data input = 7, 12, 4, 23, 10, 5, 15
                  Data terbesar ke dua = 15

Jawab :
import java.util.Scanner;

import org.apache.log4j.Logger;

/**
 * @author user
 */
public class Exercises {

 /**
  * @param args the command line arguments
  */
 private static final Logger logger = Logger.getLogger(Exercises.class);

 public static void main(String[] args) {
  Scanner input = new Scanner(System.in);

  int variable1;
  int variable2;
  int variable3;
  int variable4;
  int variable5;
  int variable6;
  int variable7;
  int x;

  System.out.print("variable1 = ");
  variable1 = input.nextInt();

  System.out.print("variable2 = ");
  variable2 = input.nextInt();

  System.out.print("variable3 = ");
  variable3 = input.nextInt();

  System.out.print("variable4 = ");
  variable4 = input.nextInt();

  System.out.print("variable5 = ");
  variable5 = input.nextInt();

  System.out.print("variable6 = ");
  variable6 = input.nextInt();

  System.out.print("variable7 = ");
  variable7 = input.nextInt();

  x = variable1;
  if (variable1 > variable2) {
   variable1 = variable2;
   variable2 = x;
  }

  x = variable2;
  if (variable2 > variable3) {
   variable2 = variable3;
   variable3 = x;
  }

  x = variable3;
  if (variable3 > variable4) {
   variable3 = variable4;
   variable4 = x;
  }

  x = variable4;
  if (variable4 > variable5) {
   variable4 = variable5;
   variable5 = x;
  }

  x = variable5;
  if (variable5 > variable6) {
   variable5 = variable6;
   variable6 = x;
  }

  x = variable6;
  if (variable6 > variable7) {
   variable6 = variable7;
   variable7 = x;
  }

  x = variable1;
  if (variable1 > variable2) {
   variable1 = variable2;
   variable2 = x;
  }

  x = variable2;
  if (variable2 > variable3) {
   variable2 = variable3;
   variable3 = x;
  }

  x = variable3;
  if (variable3 > variable4) {
   variable3 = variable4;
   variable4 = x;
  }

  x = variable4;
  if (variable4 > variable5) {
   variable4 = variable5;
   variable5 = x;
  }

  x = variable5;
  if (variable5 > variable6) {
   variable5 = variable6;
   variable6 = x;
  }

  x = variable1;
  if (variable1 > variable2) {
   variable1 = variable2;
   variable2 = x;
  }

  x = variable2;
  if (variable2 > variable3) {
   variable2 = variable3;
   variable3 = x;
  }

  x = variable3;
  if (variable3 > variable4) {
   variable3 = variable4;
   variable4 = x;
  }

  x = variable4;
  if (variable4 > variable5) {
   variable4 = variable5;
   variable5 = x;
  }

  x = variable1;
  if (variable1 > variable2) {
   variable1 = variable2;
   variable2 = x;
  }

  x = variable2;
  if (variable2 > variable3) {
   variable2 = variable3;
   variable3 = x;
  }

  x = variable3;
  if (variable3 > variable4) {
   variable3 = variable4;
   variable4 = x;
  }

  x = variable1;
  if (variable1 > variable2) {
   variable1 = variable2;
   variable2 = x;
  }

  x = variable2;
  if (variable2 > variable3) {
   variable2 = variable3;
   variable3 = x;
  }

  x = variable1;
  if (variable1 > variable2) {
   variable1 = variable2;
   variable2 = x;
  }

  System.out.println("The second large variable = " + variable6);

 }
}






3.    Buatlah program untuk menghitung n? = 1+2+3+……+n, nilai n diinputkan dari keyboard.
Contoh :     input n = 5
                  Output = 15

                  Input  = 10
                  Output = 55

Jawab :
import java.util.Scanner;

import org.apache.log4j.Logger;

/**
 * @author user
 */
public class Exercises {

 /**
  * @param args the command line arguments
  */
 private static final Logger logger = Logger.getLogger(Exercises.class);

 public static void main(String[] args) {
  Scanner input = new Scanner(System.in);

  int value;

  System.out.print("value = ");
  value = input.nextInt();

  int j = 0;
  for (int i = 1; i <= value; i++) {
   j = j + i;
   System.out.print(i + " + " + " ");
  }

  System.out.println();
  System.out.println(j + " ");

 }
}