InstanceOfJava: java programs for freshers

Java Program to check a String is palindrome or not by ignoring its case

A palindrome is a word that reads the same backward or forward.
Lets see what if the characters in a palindrome string are in different case. i.e should not be case sensitive.
So now we will see how to check a string is palindrome or not by ignoring its case.
Write a function which checks that string is palindrome or not by converting the original string to lowercase or uppercase.
Method should return true if it is palindrome, return false if not a palindrome.

#1 : Java Program to check given string is palindrome or not by ignoring its case.

package com.instanceofjava;
public class CheckPalindrome {
public static boolean isPalindrome(String str) {
StringBuffer strone=new StringBuffer(str.toLowerCase());
StringBuffer strtwo=new StringBuffer(strone);
strone.reverse();
System.out.println("Orginal String ="+strtwo);
System.out.println("After Reverse ="+strone);
if(String.valueOf(strone).compareTo(String.valueOf(strtwo))==0)
return true;
else
return false;
}
public static void main(String[] args) {
boolean ispalindrome= isPalindrome("DeleveleD");
System.out.println(ispalindrome);
}
}

Output

Orginal String =deleveled
After Reverse =deleveled
true

check palindrome or not ignore case sensitive

Remove specified element from Java LinkedHashSet example

1.Basic java example program to remove particular element in linkedhashset

boolean remove(Object o) This method used to remove specified element from Linkedhashset.

package com.removeelementLinkedhashset;
import java.util.LinkedHashSet;
import java.util.Iterator;
public class LinkedHashsetExample{
public static void main(String[] args) {
LinkedHashSet<String> linkedhashset = new LinkedHashSet<>();
linkedhashset.add("Java Interview Questions");
linkedhashset.add("Java interview program");
linkedhashset.add("Concept and example program");
linkedhashset.add("Concept and interview questions");
linkedhashset.add("Java Quiz");
System.out.println("LinkedHashSet before removal : " + linkedhashset);
boolean blnRemoved = linkedhashset.remove("Java Quiz");
System.out.println("Was Java Quiz removed from LinkedHashSet ? " + blnRemoved);
System.out.println("LinkedHashSet after removal : ");
Iterator it=linkedhashset.iterator();
while(it.hasNext()){
System.out.println(it.next());
}
}
}

Output:

LinkedHashSet before removal : [Java Interview Questions, Java interview program, Concept
and example program, Concept and interview questions, Java Quiz]
Was Java Quiz removed from LinkedHashSet ? true
Java Interview Questions
Java interview program
Concept and example program
Concept and interview questions

Basic Java Example Program to check even or add

1.Basic Java program to check even or add

package com.BasicJavaProgramsExamples;
import java.util.Scanner;
public Class EvenOrOdd{
public static void main(String args[]) {
Scanner in= new Scanner(System.in);
System.out.println("Please enter number to check even or odd");
int n=in.nextInt();
if(n%2==0){
System.out.println(+n" is even number");
} else{
System.out.println(+n" is even number");
}
}
}

Output:

Please enter number to check even or odd
4
4 is even number

2.Basic Java program to check even or add from 1 to 10

package com.BasicJavaProgramsExamples;
public Class EvenOrOdd{
public static void main(String args[]) {
for (int a=1; a<=10; a=a++){
if (a%2==0)
System.out.println(a+" is even");
else
System.out.println(a+" is odd");
}
}
}

Output:

1 is odd
2 is even
3 is odd
4 is even
5 is odd
6 is even
7 is odd
8 is even
9 is odd
10 is even

3.Basic Java program to check even or add from an array

package com.BasicJavaProgramsExamples;
import java.util.Scanner;
public Class EvenOrOdd{
public static void main(String args[]) {
int[] numbers = new int[]{1,2,3,4,5,6,7,8,9,10};
for (int a=0; a<=numbers .length; a=a++){
if (numbers[i]%2==0)
System.out.println(numbers[i]+" is even number");
else
System.out.println(numbers[i]+" is odd number");
}
}
}

Output:

1 is odd number
2 is even number
3 is odd number
4 is even number
5 is odd number
6 is even number
7 is odd number
8 is even number
9 is odd number
10 is even number

Program Check even or odd without using modulus and division operators

Java Example program to calculate area of reactangle

In this tutorial we will see how to calculate Area of Rectangle.

1.Write a Basic java example program to find area of Rectangle

To calculate the area of rectangle we need to ask user to enter length and width of the rectangle so that we can calculate area of rectangle using formula area of rectangle=length*width

package com.BasicJavaProgramsExamples;
import java.util.Scanner;
public Class AreaOfRectangle{
public static void main(String args[]) {
Scanner in= new Scanner(System.in);
System.out.println("Please enter length of a rectangle");
double length=in.nextDouble();
System.out.println("Please enter width of a rectangle");
double width=in.nextDouble();
/*
*Area of a rectangle is
*Area= length*width;
*
*/
double area=length*width;
System.out.println("Area of the Rectangle="+area);
}
}

Output:

Please enter length of a rectangle
4
Please enter width of a rectangle
8
Area of the circle =32.0

2.Write a Basic java example program to find Area of rectangle without user interaction

package com.BasicJavaProgramsExamples;
public Class AreaOfRectangle{
public static void main(String args[]) {
double length=4;
double width=8;
/*
*Area of a rectangle is
*Area= length*width;
*
*/
double area=length*width;
System.out.println("Area of the Rectangle="+area);
}
}

Output:

Area of the circle =32.0

1.Write a Basic java example program to find perimeter of Rectangle

To calculate the perimeter of rectangle we need to ask user to enter length and width of the rectangle so that we can calculate perimeter of rectangle using formula perimeter of rectangle=2*length*width

package com.BasicJavaProgramsExamples;
import java.util.Scanner;
public Class PerimeterOfRectangle{
public static void main(String args[]) {
Scanner in= new Scanner(System.in);
System.out.println("Please enter length of a rectangle");
double length=in.nextDouble();
System.out.println("Please enter width of a rectangle");
double width=in.nextDouble();
/*
*perimeter of a rectangle is
*perimeter= length*width;
*
*/
double perimeter=length*width;
System.out.println("Perimeter of the Rectangle="+perimeter);
}
}

Output:

Please enter length of a rectangle
4
Please enter width of a rectangle
8
Perimeter of the circle =64.0

Basic Java program to find area and perimeter of circle

1.Write a Basic java example program to find area of circle

To calculate the area of circle we need to ask user to enter radius of the circle so that we can calculate area of circle using formula area of circle =PI* radius * radius

package com.BasicJavaProgramsExamples;
import java.util.Scanner;
public Class AreaOfCirle{
public static void main(String args[]) {
int radius = 0;
Scanner in= new Scanner(System.in);
System.out.println("Please enter radius of a circle");
radius=in.nextInt();
/*
* where r is a radius of a circle then Area of a circle is
*Area= pi * r * r
*
*/
double area=Math.PI* radius * radius;
System.out.println("Area of the circle ="+area);
}
}

Output:

Please enter radius of a circle
23
Area of the circle =1661.9025137490005

2.Write a Basic java example program to find perimeter of circle

To calculate the perimeter of circle we need to ask user to enter radius of the circle so that we can calculate perimeter of circle using formula area of circle =2* PI* radius

package com.BasicJavaProgramsExamples;
import java.util.Scanner;
public Class PerimeterOfCirle{
public static void main(String args[]) {
int radius = 0;
Scanner in= new Scanner(System.in);
System.out.println("Please enter radius of a circle");
radius=in.nextInt();
/*
* where r is a radius of a circle then perimeter of a circle is
*Area= pi * r * r
*
*/
double perimeter =2* Math.PI* radius;
System.out.println("Perimeter of the circle ="+perimeter );
}
}

Output:

Please enter radius of a circle
12
Perimeter of the circle =75.39822368615503