An assortment of programming examples covering many different topics. Many searchable collection of source code snippets illustrating specific tasks best coding practices. With our programming samples you will be able to add your own functionality to the already existing sample. All the examples are made available here for you to copy and paste into your programs.
Free Java Source Code Links
1. Core Java Programs [PAGE 1]
2. Core Java Programs [PAGE 2]
3. Core Java Programs [PAGE 3]
4. Date Utility Code Snippet
5. String Utility Code Snippet
Core Java Programs [ PAGE 2]
Some Java programs which help lot of java beginners to understand the basic fundamentals in Java programming. Most of these programs take input from the command line. Ex - int num = Integer.parseInt(args[0]);
Program 11
/* Write a program to Concatenate string using for Loop
Example:
Input - 5
Output - 1 2 3 4 5 */
class Join{
public static void main(String args[]){
int num = Integer.parseInt(args[0]);
String result = " ";
for(int i=1;i<=num;i++){
result = result + i + " ";
}
System.out.println(result);
}
}
Program 12
/* Program to Display Multiplication Table */
class MultiplicationTable{
public static void main(String args[]){
int num = Integer.parseInt(args[0]);
System.out.println("*****MULTIPLICATION TABLE*****");
for(int i=1;i<=num;i++){
for(int j=1;j<=num;j++){
System.out.print(" "+i*j+" ");
}
System.out.print("\n");
}
}
}
Program 13
/* Write a program to Swap the values */
class Swap{
public static void main(String args[]){
int num1 = Integer.parseInt(args[0]);
int num2 = Integer.parseInt(args[1]);
System.out.println("\n***Before Swapping***");
System.out.println("Number 1 : "+num1);
System.out.println("Number 2 : "+num2);
//Swap logic
num1 = num1 + num2;
num2 = num1 - num2;
num1 = num1 - num2;
System.out.println("\n***After Swapping***");
System.out.println("Number 1 : "+num1);
System.out.println("Number 2 : "+num2);
}
}
Program 14
/* Write a program to convert given no. of days into months and days.
(Assume that each month is of 30 days)
Example :
Input - 69
Output - 69 days = 2 Month and 9 days */
class DayMonthDemo{
public static void main(String args[]){
int num = Integer.parseInt(args[0]);
int days = num%30;
int month = num/30;
System.out.println(num+" days = "+month+" Month and "+days+" days");
}
}
Program 15
/*Write a program to generate a Triangle.
eg:
1
2 2
3 3 3
4 4 4 4 and so on as per user given number */
class Triangle{
public static void main(String args[]){
int num = Integer.parseInt(args[0]);
for(int i=1;i<=num;i++){
for(int j=1;j<=i;j++){
System.out.print(" "+i+" ");
}
System.out.print("\n");
}
}
}
Program 16
/* Write a program to Display Invert Triangle.
Example:
Input - 5
Output :
5 5 5 5 5
4 4 4 4
3 3 3
2 2
1
*/
class InvertTriangle{
public static void main(String args[]){
int num = Integer.parseInt(args[0]);
while(num > 0){
for(int j=1;j<=num;j++){
System.out.print(" "+num+" ");
}
System.out.print("\n");
num--;
}
}
}
Program 17
/*Write a program to find whether given no. is Armstrong or not.
Example :
Input - 153
Output - 1^3 + 5^3 + 3^3 = 153, so it is Armstrong no. */
class Armstrong{
public static void main(String args[]){
int num = Integer.parseInt(args[0]);
int n = num; //use to check at last time
int check=0,remainder;
while(num > 0){
remainder = num % 10;
check = check + (int)Math.pow(remainder,3);
num = num / 10;
}
if(check == n)
System.out.println(n+" is an Armstrong Number");
else
System.out.println(n+" is not a Armstrong Number");
}
}
Program 18
/* Write a program to Find whether number is Prime or Not. */
class PrimeNo{
public static void main(String args[]){
int num = Integer.parseInt(args[0]);
int flag=0;
for(int i=2;i<num;i++){
if(num%i==0)
{
System.out.println(num+" is not a Prime Number");
flag = 1;
break;
}
}
if(flag==0)
System.out.println(num+" is a Prime Number");
}
}
Program 19
/* Write a program to find whether no. is palindrome or not.
Example :
Input - 12521 is a palindrome no.
Input - 12345 is not a palindrome no. */
class Palindrome{
public static void main(String args[]){
int num = Integer.parseInt(args[0]);
int n = num; //used at last time check
int reverse=0,remainder;
while(num > 0){
remainder = num % 10;
reverse = reverse * 10 + remainder;
num = num / 10;
}
if(reverse == n)
System.out.println(n+" is a Palindrome Number");
else
System.out.println(n+" is not a Palindrome Number");
}
}