10+ FIS Interview Questions and Answers

Program to find a missing number in Arrays

• Sort the array and iterate to find the missing number

• Use XOR operation to find the missing number

• Calculate the sum of all numbers and subtract from the sum of expected numbers to find the missing number

The Collection Framework is a unified architecture for representing and manipulating collections in Java.

• It provides interfaces like List, Set, Queue, etc. for storing and manipulating collections of objects.

• It also provides concrete classes like ArrayList, HashSet, PriorityQueue, etc. that implement these interfaces.

• It supports algorithms like sorting, searching, and shuffling on collections.

• It is a part of the Java Collections Framework.

• Example: List names = new ArrayList<>...read more

An abstract class is a class that cannot be instantiated and is used as a base class for other classes.

• An abstract class can have abstract and non-abstract methods.

• Abstract methods have no implementation and must be implemented by the subclass.

• A class can only extend one abstract class but can implement multiple interfaces.

• Abstract classes are used to provide a common interface for a group of related classes.

• Example: abstract class Animal { abstract void makeSound(); }

Constructor can be declared static or non-static depending on the use case.

• If a constructor is declared static, it means it can be called without creating an instance of the class.

• Static constructors are used to initialize static fields of the class.

• Non-static constructors are used to initialize instance fields of the class.

• If a class has both static and non-static constructors, the non-static constructor is called when an instance of the class is created.

Locators are used to identify web elements in Selenium.

• Locators are used to find and interact with web elements on a web page.

• There are several types of locators in Selenium, including ID, name, class name, tag name, link text, and partial link text.

• For example, to find an element with the ID 'username', you would use the ID locator: driver.findElement(By.id('username'));

Program to reverse a string

• Use a loop to iterate through the string and append each character to a new string in reverse order

• Alternatively, use built-in string reversal functions in some programming languages

To find a one element Xpath in Amazon.com

• Inspect the element in the browser

• Right-click on the element and select 'Copy XPath'

• Use the copied XPath in your code

An explicit constructor is a constructor that is defined with the 'explicit' keyword.

• It is used to prevent implicit conversions from the constructor's parameter type to the class type.

• It requires the constructor to be called explicitly with the class name and constructor arguments.

• It is commonly used to avoid unexpected type conversions and improve code clarity.

An interface in Java is a collection of abstract methods and constants that can be implemented by a class.

• An interface is declared using the interface keyword.

• It can be implemented by any class using the implements keyword.

• All methods in an interface are implicitly public and abstract.

• Interfaces can also contain constants, which are implicitly public, static, and final.

• Interfaces are used to achieve abstraction and provide a way for unrelated classes to communicate with each ...read more

Relative XPath is a way to locate elements in XML or HTML documents based on their position relative to other elements.

• Relative XPath uses the relationships between elements to navigate the document structure.

• It is more flexible than absolute XPath as it adapts to changes in the document's structure.

• Relative XPath expressions start with a reference to an element and then use various axes and predicates to locate the desired element.

• Example: //div[@class='container']/a[2] sele...read more