__As soon as you write __* Selenium Java* in your resume, interviewer is bound to give you a sheet of paper & ask write a

*. Though*

**Java program***Selenium*doesn’t require extensive Java knowledge but still there is a set of basic

*Java programs*that you should be able to write on-the-spot. This article covers five of the most popular

*questions frequently asked in the technical interview. The questions are easy, but don’t forget to mark these java-program in your to do list before attending any technical interview for*

**Write a Java program***Selenium automation testing*.

__Recursion in programming__

__Recursion in programming__

* Recursion *is a programming technique that allows the programmer to express operations in terms of themselves, i.e. a function that calls itself is known as a recursive function. A useful way to think of recursive functions is to imagine them as a process being performed where one of the instructions is to “repeat the process”.

**Write a Java program to calculate Factorial of a number**

In mathematics, the *factorial* of a non-negative integer n, denoted by n!, is the product of all positive integers less than or equal to n. For example,

5! = 5 * 4 * 3 * 2 * 1 = 120

The value of 0! is 1, according to the convention for an empty product.

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package Java; import java.util.Scanner; public class Factorial { public static int Factorial1(int a){ return (a==0 || a==1) ? 1 : (a*Factorial1(a-1)); } public static void main(String args[]){ int n; Scanner in = new Scanner(System.in); System.out.println("Enter a number: "); n = in.nextInt(); System.out.println("Factorial of "+n+" is: "+Factorial1(n)); in.close(); } } |

Use of Recursion:

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return (a==0 || a==1) ? 1 : (a*Factorial1(a-1)); |

**Write a Java program to print the Fibonacci series**

In mathematics, the *Fibonacci numbers* are the numbers in the following integer sequence, called the *Fibonacci sequence*, and characterized by the fact that every number after the first two is the sum of the two preceding ones:

*1, 1, 2, 3, 5, 8, 13, 21, 34, 55…*

By definition, the first two numbers in the *Fibonacci sequence* are either 1 and 1, or 0 and 1, depending on the chosen starting point of the sequence, and each subsequent number is the sum of the previous two.

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package Java; import java.util.Scanner; public class Fibonacci { public static int Fib(int a){ return (a<=1) ? a : Fib(a-1)+Fib(a-2); } public static void main(String args[]){ int n; Scanner in = new Scanner(System.in); System.out.println("Enter a number: "); n = in.nextInt(); for(int i=0;i<=n-1;i++) System.out.print(Fib(i)+" "); in.close(); } } |

Use of Recursion:

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return (a<=1) ? a : Fib(a-1)+Fib(a-2); |

**Write a Java program to calculate power ‘n’ of a number**

This is simple,

*2 power 5 = 2 * 2 * 2 * 2 * 2 = 32*

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package Java; import java.util.Scanner; public class PowerN { public static int Power(int x,int n){ if(n==0) return 1; else if(n==1) return x; else{ return x*Power(x,n-1); } } public static void main(String args[]){ int x,n; Scanner in = new Scanner(System.in); System.out.println("Enter a number: "); x = in.nextInt(); System.out.println("Enter the power: "); n = in.nextInt(); System.out.println("Number "+x+" to the power "+n+" is: "+Power(x,n)); in.close(); } } |

Use of Recursion:

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return x*Power(x,n-1); |

**Write a Java program to Reverse a String**

Although there are many ways to get the solution but we are sharing 2 different ways to *reverse a string*. First we will understand the question,

*Input: Deepanshu Agarwal | Output: lawragA uhsnapeeD*

*Input: Software Testing Studio | Output: oidutS gnitseT erawtfoS*

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package Java; import java.util.Scanner; public class ReverseString { public static String Reverse1(String a){ String reverse = ""; int len = a.length(); for (int i = len - 1 ; i >= 0 ; i-- ) reverse += a.charAt(i); return reverse; } public static StringBuffer Reverse2(String a){ StringBuffer sb = new StringBuffer(a); return sb.reverse(); } public static void main(String args[]){ String original; Scanner in = new Scanner(System.in); System.out.println("Enter a string to reverse: "); original = in.nextLine(); System.out.println("Reverse of entered string is: "+Reverse1(original)); System.out.println("Reverse of entered string is: "+Reverse2(original)); in.close(); } } |

This java program reverses a string entered by the user. We use,

**charAt**method to extract characters from the string and append them in reverse order to reverse the entered string**StringBuffer**class method

**Write a Java program to calculate ‘Digit Sum’**

You’re given an integer N. Write a Java program to calculate the sum of all the digits of N. In mathematics, the *digit sum* of a given integer is the sum of all its digits (e.g. the *digit sum* of 84001 is calculated as 8+4+0+0+1 = 13).

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package Java; import java.util.Scanner; public class SumofDigits { public static int sum(int n){ return n==0 ? 0 : n%10+sum(n/10); } public static void main(String[] args) { Scanner sc = new Scanner(System.in); System.out.println("Enter a number: "); int num = sc.nextInt(); sc.close(); System.out.println("Sum of digits of "+num + " is: " + sum(num)); } } |

Hope these five programs will help you kick-start the Java-program journey. All the Best 🙂

Hi will share string programs in java for interview

How many objects will be created If two Strings are Created This way

String S1 = “beyond_corner”;

String S2 = “beyond_corner”;

only one object is created, because s1 and s2 are string literals and having the same content object reference will be shared by them in the string pool.

Nice article,

I was searching for something like this i was browsing the net since ours but din’t find exact question and answers which justifies the question your article is the best and have all the important questions include in it.