Printing odd numbers up-to a given number

 import java.util.*;

public class PrintOddNum{

public static void main(String args[]){

Scanner sc = new Scanner(System.in);

System.out.println("Enter the no up to which odd no is to be printed");

int n = sc.nextInt();

System.out.print("List of odd is :");

for(int i=0; i<=n; i++){

if(i%2 != 0){

System.out.println(i);

}

}

}

}

Printing factor of two numbers up to 100

 import java.util.*;

public class PrintFactor{

public static void main(String args[]){

Scanner sc = new Scanner(System.in);

System.out.println("Enter the first number");

int a = sc.nextInt();

System.out.println("Enter the Second number");

int b = sc.nextInt();

System.out.println("No divisible by "+a);

for(int i=1; i<=100; i++){

if (i%a == 0){

System.out.print(i+",");

}

}

System.out.println();

System.out.println("No divisible by "+b);

for(int i=1; i<=100; i++){

if (i%b == 0){

System.out.print(i+",");

}

}

System.out.println();

System.out.println("No divisible by "+a +","+b);

for(int i=1; i<=100; i++){

if (i%a == 0 && i%b ==0){

System.out.print(i+",");

}

}

}

}

Printing current time and date

 public class PrintCurrentTime {

public static void main(String[] args){

System.out.format("\nCurrent Date time: %tc%n\n", System.currentTimeMillis());

}

}

Swapping

 import java.util.*;

public class swapping{

public static void main(String args[]){

Scanner sc = new Scanner(System.in);

System.out.println("Enter first number");

int a = sc.nextInt();

System.out.println("Enter Second number");

int b = sc.nextInt();

System.out.println("Before swapping : a, b = "+a+","+b);

//swapping

int temp = a;

a = b;

b= temp;

System.out.print("After swapping : a, b = "+a+","+b);

}

}

Spiral Matrix

 

import java.util.*;

public class ArraysSpiral {

public static void main(String args []){

Scanner sc = new Scanner(System.in);

int n = sc.nextInt();

int m = sc.nextInt();

int matrix[][] = new int[n][m];

for(int i=0; i<n; i++){

for(int j=0; j<m; j++){

matrix[i][j] = sc.nextInt();

}

}

System.out.println("The spiral Order Matrix is:");

int rowStart = 0;

int rowEnd = n-1;

int colStart = 0;

int colEnd = m-1;

//to print spiral matrix

while(rowStart <= rowEnd && colStart <= colEnd){

//1

for(int col=colStart; col<=colEnd; col++){

System.out.print(matrix[rowStart][col] + " ");

}

rowStart++;

//2

for(int row=rowStart; row<=rowEnd; row++){

System.out.print(matrix[row][colEnd] + " ");

}

colEnd--;

//3

for(int col=colEnd; col>=colStart; col--){

System.out.print(matrix[rowEnd][col] + " ");

}

rowEnd--;

//4

for(int row=rowEnd; row>=rowStart; row--){

System.out.print(matrix[row][colStart] + " ");

}

colStart++;

System.out.println();

}

}

}

Searching the index of an element in a given array

 import java.util.*;

public class Arrays2 {

public static void main(String args[]){

Scanner sc = new Scanner(System.in);

System.out.println("Enter the size of array");

int size = sc.nextInt();

System.out.println("Enter the element of array");

int numbers[] = new int[size];

//input

for(int i=0; i<size; i++){

numbers[i] = sc.nextInt();

}

System.out.println("Enter the number to be found");

int x = sc.nextInt();

//output

for(int i=0; i<numbers.length; i++){

if(numbers[i] == x){

System.out.print("x is found at index :"+i);

}

}

}

}

Printing sum of two numbers

 import java.util.*;

public class Sum2Num{

public static void main(String args[]){

Scanner sc = new Scanner(System.in);

int a = sc.nextInt();

int b = sc.nextInt();

int sum = a + b;

System.out.print("The sum of a and b is :" + sum);

}

}

Printing the table of a given number

 import java.util.*;

public class Table{

public static void main(String args[]){

Scanner sc = new Scanner(System.in);

System.out.print("Enter the number");

int n = sc.nextInt();

for(int i=1; i<=10; i++){

System.out.println(n+"*"+i+"="+n*i);

}

}

}

Printing the division result of two numbers.

 import java.util.*;

public class printDiv{

public static void main(String args[]){

Scanner sc = new Scanner(System.in);

int a = sc.nextInt();

int b = sc.nextInt();

int div = a / b;

System.out.print("The division of a by b is:" + div);

}

}

Calculating radius and area of a circle.

 import java.util.*;

public class printCir{

public static void main(String args []){

Scanner sc = new Scanner(System.in);

double Radius = sc.nextDouble();

//double perimeter = 2*Math.PI*Radius;

//double area = Math.PI*Radius*Radius;

System.out.println("Perimeter of circle is :"+2*Math.PI*Radius);

System.out.print("Area of Circle is :"+Math.PI*Radius*Radius);

}

}

Calculating area and perimeter of a Rectangle

 import java.util.*;

public class printRect{

public static void main(String args []){

Scanner sc = new Scanner(System.in);

double Width = sc.nextDouble();

double Height = sc.nextDouble();

System.out.println("Perimeter of Rectangle is :"+2*(Width+Height));

System.out.print("Area of Rectangle is :"+Width*Height);

}

}

Calculations using BODMAS

 import java.util.*;

public class printOper{

public static void main(String args[]){

System.out.println(-5+8*6);

System.out.println((55+9)%9);

System.out.println(20+(-3*5)/8);

System.out.println(5+15/3*2-8%3);

}

}

Multiplication of two numbers

 import java.util.*;

public class printMul{

public static void main(String args[]){

Scanner sc = new Scanner(System.in);

System.out.println("Enter the first number");

int a = sc.nextInt();

System.out.println("Enter the second number");

int b = sc.nextInt();

int mul = a * b;

System.out.print("The result of a x b is:" + mul);

}

}

Printing pattern Java

 public class printJava{

public static void main(String args[]){

System.out.println(" J a v v a ");

System.out.println(" J a a v v a a");

System.out.println("J J aaaaa V V aaaaa");

System.out.println(" JJ a a V a a");

}

}

Printing sum of user given input

 import java.util.*;

public class printSum{

public static void main(String args[]){

Scanner sc = new Scanner(System.in);

int a = sc.nextInt();

int b = sc.nextInt();

int sum = a + b;

System.out.print("The sum of a + b is:" + sum);

}

}

Defining and Printing Array

 

import java.util.*;

public class Arrays {

public static void main(String args[]){

// int [] marks = new int[3];

// int marks [] = new int[3]; //This is also a valid syntax

int marks[] ={97, 98, 95};

// marks[0] = 97; //physics

// marks[1] = 98; //chemisty

//marks[2] = 95; // maths

//System.out.println(marks[0]);

//System.out.println(marks[1]);

//System.out.println(marks[2]);

for(int i=0; i<3; i++){

System.out.println(marks[i]);

}

}

}