Top 10 Basic Java Programs : Asked In Java Interview

                  

Top 10 Basic Java Programs

      Here is the Top 10 Basic Java Programs to tackle any Java  technical interview ,it will also help to understand basic Java Concepts ,this Programs  are ask in Various Technical Interview Over the Year Whether you are Fresher or experience one, in interview or any Programming test this kind of questions you may face. So please take a look and if you have any Question Please comment below.

Happy Learnings!!!

1. Write a Program for Swapping the number without using third variable

Program:

class SwapWithoutThirdVariable
{
public static void main( String args[ ] )
{
int   a, b;

a = 10;
b = 20;

System.out.print("\nBefore Swapping : " );
System.out.print( a + "   " + b );

a = a + b;
b = a - b;
a = a - b;

System.out.print( "\nAfter Swapping  : " );
System.out.print( a + "   " + b );
}
}

Output:

Before Swapping :  10 20

After Swapping  : 20 10

2.Write a Program for Swapping example with using  third variable

Program  :

class SwapWithoutThirdVariable
{
public static void main( String args[ ] )
{
int   a, b, t ;

a = 10;
b = 20;

System.out.print("\nBefore Swapping : " );
System.out.print( a + "   " + b );

a=t;
a=b;
b=t;

System.out.print( "\nAfter Swapping  : " );
System.out.print( a + "   " + b );
}
}

Output:

Before Swapping :  10 20

After Swapping  : 20 10

3.Write a  Program to Calculate the Fibonacci Series.

Program :

class  FibonacciTest
{
public static void main( String args[ ] )
{
int n, i , a = 0, b = 1, c = 0;
 
n = 6;

System.out.print( " " + a + " " + b );
for( i=1 ; i<=(n-2) ; i++ )
   {
c = a + b;
System.out.print( " " + c );
a = b;
b = c;
   }
   }
}

Output :
0  1  1  2  3  5

4.Write a Program to Check the Given Number is PRIME or NOT.

Program:

class  PrimeTest
{
public static void main( String args[ ] )
{
int i, n;
boolean  flag = true;

n = 29;

for( i=2 ; i<=n/2 ; i++ )
{
if( n % i == 0 )
{
flag = false;
break;
}
}

if( flag == true )
System.out.print( "\n Number " + n + " is a PRIME Number." );
else
System.out.print( "\n Number " + n + " is NOT a PRIME Number." );
}
}

Output:

Number 29 is a PRIME Number.

5.Write a Program for  sum of numbers using command line

Program :

class  ArguSum
{
   public static void main( String args[ ] )
   {
int  s = 0, len;
len = args.length;
 
for( int i=0 ; i<len ; i++ )
{
int  x = Integer.parseInt( args[ i ] );
s = s + x;
}
System.out.println( " Sum of Command-Line Arguments ::: " + s );
  }
}

Output:

D:\Java Examples\java ArguSum.java 1 2 3 4 5 6 7 8 9 10
Sum of Command-Line Arguments ::: 55

6.Write a Program to Calculate the Factorial of the Given Number.

Program :

class  FactorialTest
{
public static void main( String args[ ] )
{
int i, n;

n = 5;

int f = 1;
for( i=n ; i>=1 ; i-- )
{
f = f * i ;
}
System.out.println( "\n The Factorial of " + n + " is = " + f );
}
}

Output:

The Factorial of 5 is = 120

7.Write a  Program to check whether a given Number is ArmStrong Number or not.

Program :

class  ArmstrongTest
{
public static void main( String args[ ] )
{
int r, n, x, sum;

n = 153;
x = n;

sum = 0;
while( n != 0 )
{
r = n % 10;
sum = sum + ( r * r * r );
n = n / 10;
}

if( sum == x )
System.out.println( " Number " + x + " is a Amstrong Number." );
else
System.out.println( " Number " + x + " is NOT a Amstrong Number." );
}
}

Output: 153 is Armstrong Number

8.Write a Program to check given number is palindrom or not

Program:

public class PalindromeNumber {

    public static void main(String[] args) {
        int n = 1215;
        int sum = 0;
        int m = n;

        while (n > 0) {
            //int sum=0;
            int r = n % 10;
            sum = sum * 10 + r;
            n = n / 10;

        }
        if (m == sum) {
            System.out.println("palindrome");
        } else {
            System.out.println("not palindrome");
        }
    }
}

Output:

not palindrome

9.Write a Program for  sum of even odd using while loop

Program :

class OddEvenSum {

    public static void main(String[] args) {

        int i;
        int sum = 0;
        int sum1 = 0;
        for (i = 0; i <= 10; i++) {
            if (i % 2 == 0) {
                sum = sum + i;
            } else {
                sum1 = sum1 + i;
            }
        }
        System.out.println("sum of even nos is : " + sum);
        System.out.println("sum of odd nos is : " + sum1);
    }
}

Output:

sum of even nos is : 30
sum of odd nos is : 25

10.Write a program to count number of given digits

Program :

class  NumberOfDigits
{
public static void main( String args[ ] )
{
int n, c;

n = 1234;

c = 0;
while( n != 0 )
{
n = n / 10;
c++;
}
System.out.println( " Number of Digits : " + c );
}
}

Output:

Number of Digits : 4