Top 10 Java Programs

Top 10 Program in Java

Here we discuss about Top 10 Programs in Java. Generally in java from control statements, array, string, oops etc related programs asked in any interview.

1. Armstrong Program in Java

import java.util.Scanner;
class Armstrong 
{
 public static void main(String[] args)
{
int arm=0,a,b,c,d,no; 
Scanner s=new Scanner(System.in);
System.out.println("Enter any num :");
no=s.nextInt();
d=no;
while(no>0)
{
a=no%10;
no=no/10;
arm=arm+a*a*a;
}
if(arm==d)
{
System.out.println("Armstrong :");
}
else
{
System.out.println("not Armstrong");
}
}
}

Enter any num :
153
Armstrong

2. Prime Number Program in Java

Prime number is a number which is divisible by 1 and itself. Prime number cannot be divisible by other numbers except 1 or itself. Prime number start from 2, 3, 5, 7, 11, 13, 17, 19.....etc. 0 and 1 are not a prime number.

import java.util.Scanner;
class Primenumber 
{
public static void main(String[] args) 
{
int no, i, fect=1;
Scanner s=new Scanner(System.in);
System.out.println("Enter any number :");
no=s.nextInt();
  if(no==1)
  {
  System.out.println("Smallest Prime number is 2");
  }
  for(i=2;i<no;i++)
  {
  if(no%i==0)
  {
  System.out.println("Not Prime");
  break;
  }
  }
 if(no==i)
 {
 System.out.println("Prime");
 }
}
}

Enter any number :
7
Prime

3. Factorial Program in Java

import java.util.Scanner;
class Factorial
{
	public static void main(String[] args) 
	{
    int no, fect=1;
	Scanner s=new Scanner(System.in);
    System.out.println("Enter any number :");
	no=s.nextInt();
    for(int i=1; i<=no; i++)
	{
	fect=fect*i;
	}
	System.out.println("Factorial is :" +fect);
	}
}

Enter any number :
6
Factorial is :
720

4. Reverse Number Program in Java

import java.util.Scanner;
class Reverse 
{
public static void main(String[] args) 
{
int no,rev=0,r,a;
Scanner s=new Scanner(System.in);
System.out.println("Enter any no.: ");
no=s.nextInt();
a=no;
while(no>0)
{
r=no%10;
rev=rev*10+r;
no=no/10;
}
System.out.println("Reverse: "+rev);
}
}

Enter any no. :
153
Reverse: 351

5. Palindrome Number Program in Java

Palindrome number is a number that remains the same after reverse. for example : 151, 242, 585, 3333, etc.

import java.util.Scanner;
class Palindrome 
{
public static void main(String[] args) 
{
int a,no,b,temp=0;
Scanner s=new Scanner(System.in);
System.out.println("Enter any num: ");
no=s.nextInt();
b=no;
while(no>0)
{
a=no%10;
no=no/10;
temp=temp*10+a;
}
if(temp==b)
{
System.out.println("Palindrome");
}
else
{
System.out.println("not Palindrome");
}
}
}

Enter any num :
151
Palindrome

6. Sort an Array Elements in Ascending Order in Java

import java.util.Scanner;
public class SortArray 
{
  public static void main(String[] args) 
  {
   int n, temp;
   Scanner s = new Scanner(System.in);
   System.out.print("Enter no. of elements you want in array:");
   n = s.nextInt();
   int a[] = new int[n];
   System.out.println("Enter all the elements:");
   for (int i=0; i<n; i++) 
    {
    a[i]=s.nextInt();
    }
    for (int i =0; i<n; i++) 
    {
    for (int j=i+1; j<n; j++) 
    {
    if (a[i]>a[j])  // compare numbers
    {
     temp=a[i];
     a[i]=a[j];
     a[j]=temp;
    }
   }
  }
  System.out.print("Elements in Ascending Order:");
  for (int i=0; i<n-1; i++) 
  {
  System.out.print(a[i]+ ", "); // print in same line and separate with comma
 }
  System.out.print(a[n-1]);
 }
}

Enter no. of elements you want in array: 5
3
4
1
7
6
Elements in Ascending Order:
1, 3, 4, 6, 7

7. Java Program to Find Odd or Even

import java.util.Scanner;
class Oddeven 
{
	public static void main(String[] args) 
	{
    int no;
	Scanner s=new Scanner(System.in);
    System.out.println("Enter any number :");
	no=s.nextInt();
    if(no%2==0)
	{
	System.out.println("Even number");
	}
	else
	{
	System.out.println("Odd number");
	}
	}
}

Enter any number : 
10
Even number

8. Print Table of Number in Java

import java.util.Scanner;
class Table 
{
public static void main(String[] args) 
{
int i,no,table=1;
Scanner s=new Scanner(System.in);
System.out.println("Enter any number: ");
no=s.nextInt();
for(i=1; i<=10; i++)
{
table=no*i;
System.out.println(table);
}
}
}

Enter any number :
5
5
10
15
20
25
30
35
40
45
50

9. Fibonacci Series Program in Java

import java.util.Scanner;
class Fibonacci 
{
public static void main(String[] args) 
{
int i,no, first=0, second=1, next;
Scanner s=new Scanner(System.in);
System.out.println("Enter number of terms for Series: ");
no=s.nextInt();
first=0;
second=1;
System.out.println("Fibonacci series are: ");
 for(i=0; i<no; i++)
 {
  System.out.println(first);
  next = first + second;
  first = second;
  second = next;
  }
}
}

Enter nubmer of terms for Series: 
5
Fibonacci series are:
0
1
1
2
3

10. Java Program to Find sum of Digits

import java.util.Scanner;
class Sumofdigit
{
public static void main(String[] args) 
{
int a,no,sum=0;
Scanner s=new Scanner(System.in);
System.out.println("Enter any number: ");
no=s.nextInt();
while(no>0)
{
a=no%10;
no=no/10;
sum=sum+a;
}
System.out.println("Sum of Digits :"+sum);
}
}

Enter Value in a :
10
Enter Value in b :
20
Value in a : 20
Value in b : 10