Core Java

Java program to generate random numbers

Objectives:

Write a Java program to to generate random numbers and print the same
Write a program to generate random numbers
Write a program to generate random numbers in Java

Java Program:

[sourcecode lang="java"]

import java.util.Scanner;
import java.util.Random;

class GenerateRandomNumber
{
public static void main(String[] args)
{
int maxRange;

//create objects
Scanner SC = new Scanner(System.in);
Random rand = new Random();

System.out.print("Please enter maximum range: ");
maxRange=SC.nextInt();

for(int i=1; i<=10; i++)
{
System.out.println(rand.nextInt(maxRange));
}
}
}

[/sourcecode]

Output:

Please enter maximum range: 500
467
61
100
449
68
316
445
224
54
498

Find duplicate characters in string

Objectives:

Write a Java program to find duplicate characters in the string and print the duplicate characters
Write a program to find duplicate characters in String

Java Program:

[sourcecode lang="java"]
public class DuplicateCharacters {
    public static void main(String args[]) {

        String str = "NITIN";
        int count = 0;

        char input[] = str.toCharArray();
        System.out.println("Duplicate Characters are:");

        for (int i = 0; i &amp;lt; str.length(); i++) {
            for (int j = i + 1; j &amp;lt; str.length(); j++) {
                if (input[i] == input [j]) {
                    System.out.println(input[j]);
                    count++;
                    break;
                }
           }
        }
    }
}
[/sourcecode]

Output:

Duplicate Characters are: N I

Pattern Programs in Java – Pattern 2

Pattern 2 :

1
2 2
3 3 3
4 4 4 4
5 5 5 5 5

Java Program for the above pattern:

[sourcecode language=”java”]

import java.util.Scanner;

public class MainClass

{

public static void main(String[] args)

{

Scanner sc = new Scanner(System.in);

//Taking rows value from the user
System.out.println("How many rows you want in this pattern?");

int rows = sc.nextInt();

System.out.println("Here is your pattern….!!!");

for (int i = 1; i <= rows; i++)

{

for (int j = 1; j <= i; j++)

{

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

}

System.out.println();

}

//Close the resources
sc.close();

}

[/sourcecode]

June 11, 2018 by Aatul Palandurkar How to's Java Source Code Java Tutorials 0

Java Program to convert Decimal to Binary

Objectives :

Decimal to Binary Conversion
Converting Decimal to Binary
Converting Decimal Number to Binary format
Write a program to convert decimal to binary
Write a program to convert decimal number to binary format
Write a program to convert positive decimal number to binary format
Write a program to convert decimal to binary using Scanner class
Write a program to convert decimal to binary, take input using Scanner class

Java Program to convert Decimal to Binary :

[sourcecode lang=”java”]
public class DecimalToBinary {

public void toBinary(int number){
int binary[] = new int[25];
int n = 0;
// Convert Decimal to Binary
while(number > 0){
binary[n++] = number%2;
number = number/2;
}
// Print Binary number
for(int i = n-1;i >= 0;i–){
System.out.print(binary[i]);
}
}

public static void main(String[] args){
DecimalToBinary obj = new DecimalToBinary();
obj.toBinary(14);
}
}
[/sourcecode]

Output :

1110

Java Program to convert Decimal to Binary using Scanner class :

[sourcecode lang=”java”]

import java.util.Scanner;

public class DecimalToBinary {

public void toBinary(int number){
int binary[] = new int[14];
int n = 0;

// Convert Decimal to Binary
while(number > 0){
binary[n++] = number%2;
number = number/2;
}

// Print Binary Number
for(int i = n-1;i >= 0;i–){
System.out.print(binary[i]);
}
}

public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
System.out.print("Enter a number: ");
int num= scanner.nextInt();
DecimalToBinary obj = new DecimalToBinary();
obj.toBinary(num);

}
}

[/sourcecode]

Output :

Enter a number: 14

1110

March 15, 2016 by Aatul Palandurkar Java Tutorials 1

Simple Interest Example in Java

Starting a series of some Java programs as many students were asking to share the programs. Here is the first program of the series.

Objectives:

Write a Program that calculates and prints the simple interest using the formula : Simple Interest = PTR/100
How to calculate Simple Interest in Java?
Write a program to calculate Simple Interest in Java.
Write a Java program that calculates and prints the simple interest using the formula : “SimpleInterest = PTR/100” and input values P, T, R should be accepted as command line.
How to use Command Line Arguments in Java?
How to pass values from command line in Java?
How to take input in Java from console?

This particular program can be written in various ways, we will try to write the solution program in different ways here and one can try to understand the difference between them.

Method 1 :

[sourcecode lang=”java”]
import java.util.Scanner;

public class SimpleInterestExample {

public static void main(String[] args) {

int p,t,r, result;

Scanner sc = new Scanner(System.in);

System.out.println("Enter the Value of P : ");
p = sc.nextInt();

System.out.println("Enter the Value of T : ");
t = sc.nextInt();

System.out.println("Enter the Value of R : ");
r = sc.nextInt();

result = (p*t*r)/100;
System.out.println("Interest is : " + result);
}
}
[/sourcecode]

This one is the simplest way to write the program to find simple interest in Java. Here we have simply created the object of Scanner class for taking input. Scanner class was introduced in Java 6. To use Scanner class we will have to import the class from java.util package.

Method 2:

Now we will write a Java program that calculates and prints the simple interest using the Scanner class again but with object oriented programming approach.

[sourcecode lang=”java”]
import java.util.Scanner;

public class SimpleInterestExample
{
double principalAmount = 0;
double interestRate = 0;
double term = 0;
double simpleInterest = 0;

public void calculateSimpleInterest()
{
Scanner input = new Scanner(System.in);

System.out.print("Enter the Principal amount : ");
principalAmount = input.nextDouble();

System.out.print("Enter the Rate As a decimal : ");
interestRate = input.nextDouble();

System.out.print("Enter the amount of time in years : ");
term = input.nextDouble();

simpleInterest = (principalAmount * interestRate * term) / 100;
}

public void displaySimpleInterest()
{
System.out.println("The Simple Interest is : " + simpleInterest);
}
}
[/sourcecode]

Mock Test Program for above code so that we can test the code. keep both the classes in same package and run the Mock Test Program or MockTestProgram.java

[sourcecode lang=”java”]
public class MockTestProgram{

public static void main(String[]args);
{
SimpleInterestExample simpleInt = new SimpleInterestExample();
simpleInt.calculateSimpleInterest();
simpleInt.displaySimpleInterest();
}
}
[/sourcecode]

Method 3:

Now we will write a Java program that calculates and prints the simple interest using the formula : “SimpleInterest = PTR/100” and input values P, T, R should be accepted as command line.

[sourcecode lang=”java”]
import java.util.Scanner;

public class SimpleInterestExample {

public static void main(String[] args) {
double p,t,r, result;

p = Double.parseDouble(args[0]);
t = Double.parseDouble(args[1]);
r = Double.parseDouble(args[2]);

Scanner sc = new Scanner(System.in);

System.out.println("Enter the Value of P : ");
p = sc.nextDouble();

System.out.println("Enter the Value of T : ");
t = sc.nextDouble();

System.out.println("Enter the Value of R : ");
r = sc.nextDouble();

result = (p*t*r)/100;
System.out.println("Interest is : " + result);
}
}
[/sourcecode]

I will be sharing more programs soon as many students were asking for programs which were carried out during Java training and were asked in assignments after Java training. By the time enjoy coding in Java and use NetBeans, it will ease your life.

July 20, 2015 by Aatul Palandurkar Java Source Code Java Tutorials 0

Core Java Workshop at TGPCET

Conducted a Workshop on Core Java at Tulsiramji Gaikwad Patil College of Engineering & Technology, Nagpur on 25 Mar. 2013 & 26 Mar. 2013. It was nice to provide Classroom Training & Workshop on Core Java to students of TGPCET.

Have a look at glimpse of workshop here :

[gigya src=”http://player.videofy.me/player.swf?videoId=1100848″ width=”480″ height=”360″ quality=”high” wmode=”transparent” allowFullScreen=”true”]

Watch this as You Tube video:

[youtube http://www.youtube.com/watch?v=NhnIxMeX4Hc&w=420&h=315]

March 26, 2013 by Aatul Palandurkar Workshop 3

Why Java is Platform Independent?

Objectives :

Why Java is platform independent?
How java program executes?
What is execution flow of Java Program?
What are the steps to execute a Java Program?
What are the steps to run a Java Program?

[gigya src=”http://player.videofy.me/player.swf?videoId=424278″ width=”480″ height=”300″ quality=”high” wmode=”transparent” allowFullScreen=”true” ]

March 3, 2012 by Aatul Palandurkar Java Tutorials Video Tutorials 14

HelloWorld – Core Java Tutorial

Objective :

How to write a simple Java program?
How to write Hello in Java?
How to write HelloWorld in Java?
How to write & execute a simple Java program?
How to write Java program using Notepad & execute using Command Prompt?

[youtube:http://www.youtube.com/watch?v=WF0vl4x8Dm0]

Posted from WordPress for Android

January 10, 2012 by Aatul Palandurkar How to's Java Tutorials Video Tutorials 0

Data Types in Java

In Java there are total 8 data types available which are further divided into 4 groups viz. integers, floating point numbers, character & boolean values.

Type	Size in Bytes (Bits)	Range	Default value	Contains
Integers
Byte	1 byte (8 bits)	-128 to 127	0	Signed Integer
Short	2 bytes (16 bits)	-32768 to 32767	0	Signed Integer
Int	4 bytes (32 bits)	-2147483648 to 2147483647	0	Signed Integer
Long	8 bytes (64 bits)	-9223372036854775808 to 9223372036854775807	0	Signed Integer
Floating point numbers
Float	4 bytes (32 bits)	-3.4e³⁸ to 3.4e³⁸ (i.e. 3.4*10¹⁷)	0.0	IEEE754 Floating point number
Double	8 bytes (64 bits)	-1.7e³⁰⁸ to 1.7e³⁰⁸ (i.e. 1.7*10¹⁵¹)	0.0	IEEE754 Floating point number
Characters
char	2 bytes (16 bits)	\u0000 to \uFFFF	\u0000	Unicode Characters
Boolean values
boolean	1 bit	Not Applicable	False	true or false
Table : Data Types in Java

October 17, 2011 by Aatul Palandurkar Java Java Tutorials 0

How to set Path for Java

Dear Friends,

If you want to set the path for Java, there are two main types for setting system path for Java which are as follows;

Temporary Path
Permanent Path

For the above two types, the video describes the complete step by step procedure for setting path for Java :

[youtube=http://www.youtube.com/watch?v=rM4Qq3Ua7Sk]

Or you can go through this tutorial :

1. To check path is set or not :

a. Go to Start Menu

b. Go to Run

c. Type “cmd” without quotes to open Command prompt.

d. Get to the root directory say c:/>

e. To check whether the path is already set or not, on command prompt type “javac” without quotes & press enter/return. If the following message appears on the console screen then the path is not set.