Selenium Interview Questions Part I

What is Automation Testing?

Automation testing or Test Automation is a process of automating the manual process to test the application/system under test. Automation testing involves use to a separate testing tool which lets you create test scripts which can be executed repeatedly and doesn’t require any manual intervention.

What are the benefits of Automation Testing?

Benefits of Automation testing are:

  1. Supports execution of repeated test cases

  2. Aids in testing a large test matrix

  3. Enables parallel execution

  4. Encourages unattended execution

  5. Improves accuracy thereby reducing human generated errors

  6. Saves time and money

Learn more about Selenium

What are the testing types that can be supported by Selenium?

Selenium supports the following types of testing :

  • Functional Testing

  • Regression Testing

What are the limitations of Selenium?

Following are the limitations of Selenium :

  • Selenium supports testing of only web based applications

  • Mobile applications cannot be tested using Selenium

  • Captcha and Bar code readers cannot be tested using Selenium

  • Reports can only be generated using third party tools like TestNG or Junit

  • As Selenium is a free tool, thus there is no ready vendor support though the user can find numerous helping communities

  • User is expected to possess prior programming language knowledge

Why should Selenium be selected as a test tool?

Selenium

  1. is free and open source

  2. have a large user base and helping communities

  3. have cross Browser compatibility (Firefox, chrome, Internet Explorer, Safari etc.)

  4. have great platform compatibility (Windows, Mac OS, Linux etc.)

  5. supports multiple programming languages (Java, C#, Ruby, Python, Pearl etc.)

  6. has fresh and regular repository developments

  7. supports distributed testing

What is Selenium? What are the different Selenium components?

Selenium is one of the most popular automated testing suites. Selenium is designed in a way to support and encourage automation testing of functional aspects of web based applications and a wide range of browsers and platforms. Due to its existence in the open source community, it has become one of the most accepted tools amongst the testing professionals.

Selenium is not just a single tool or a utility, rather a package of several testing tools and for the same reason it is referred to as a Suite. Each of these tools is designed to cater different testing and test environment requirements.

The suite package constitutes of the following sets of tools :

  • Selenium Integrated Development Environment (IDE) – Selenium IDE is a record and playback tool. It is distributed as a Firefox Plugin.

  • Selenium Remote Control (RC) – Selenium RC is a server that allows user to create test scripts in a desired programming language. It also allows executing test scripts within the large spectrum of browsers.

  • Selenium WebDriver – WebDriver is a different tool altogether that has various advantages over Selenium RC. WebDriver directly communicates with the web browser and uses its native compatibility to automate.

  • Selenium Grid – Selenium Grid is used to distribute your test execution on multiple platforms and environments concurrently.

What do we mean by Selenium 1 and Selenium 2?

Selenium RC and WebDriver, in a combination are popularly known as Selenium 2. Selenium RC alone is also referred as Selenium 1.

When should I use Selenium IDE?

Selenium IDE is the simplest and easiest of all the tools within the Selenium Package. Its record and playback feature makes it exceptionally easy to learn with minimal acquaintances to any programming language. Selenium IDE is an ideal tool for a naïve user.

Learn about Java in detail

How do I launch the browser using WebDriver?

The following syntax can be used to launch Browser :

What are the different types of Drivers available in WebDriver?

The different drivers available in WebDriver are :

  • FirefoxDriver

  • InternetExplorerDriver

  • ChromeDriver

  • SafariDriver

  • OperaDriver

  • AndroidDriver

  • IPhoneDriver

  • HtmlUnitDriver

What is Selenese?

Selenese is the language which is used to write test scripts in Selenium IDE.

What are the different types of waits available in WebDriver?

There are two types of waits available in WebDriver:

  1. Implicit Wait

  2. Explicit Wait

Implicit Wait : Implicit waits are used to provide a default waiting time (say 30 seconds) between each consecutive test step/command across the entire test script. Thus, subsequent test step would only execute when the 30 seconds have elapsed after executing the previous test step/command.

Explicit Wait : Explicit waits are used to halt the execution till the time a particular condition is met or the maximum time has elapsed. Unlike Implicit waits, explicit waits are applied for a particular instance only.

How to type in a textbox using Selenium?

User can use sendKeys(“String to be entered”) to enter the string in the textbox.

Syntax :

What is the purpose of test design technique?

Locator can be termed as an address that identifies a web element uniquely within the webpage. Thus, to identify web elements accurately and precisely we have different types of locators in Selenium:

  • ID

  • ClassName

  • Name

  • TagName

  • LinkText

  • PartialLinkText

  • Xpath

  • CSS Selector

  • DOM

What studies data flow analysis?

The use of data on paths through the code.

What is difference between assert and verify commands?

Assert :
Assert command checks whether the given condition is true or false. Let’s say we assert whether the given element is present on the web page or not. If the condition is true then the program control will execute the next test step but if the condition is false, the execution would stop and no further test would be executed.

Verify :
Verify command also checks whether the given condition is true or false. Irrespective of the condition being true or false, the program execution doesn’t halts i.e. any failure during verification would not stop the execution and all the test steps would be executed.

When should I use Selenium Grid?

Selenium Grid can be used to execute same or different test scripts on multiple platforms and browsers concurrently so as to achieve distributed test execution, testing under different environments and saving execution time remarkably.

What is an Xpath?

Xpath is used to locate a web element based on its XML path. XML stands for Extensible Markup Language and is used to store, organize and transport arbitrary data. It stores data in a key-value pair which is very much similar to HTML tags. Both being markup languages and since they fall under the same umbrella, Xpath can be used to locate HTML elements.

The fundamental behind locating elements using Xpath is the traversing between various elements across the entire page and thus enabling a user to find an element with the reference of another element.

How can you find if an element in displayed on the screen?

WebDriver facilitates the user with the following methods to check the visibility of the web elements. These web elements can be buttons, drop boxes, checkboxes, radio buttons, labels etc.

  1. isDisplayed()

  2. isSelected()

  3. isEnabled()

Syntax :

How can we get a text of a web element?

Get command is used to retrieve the inner text of the specified web element. The command doesn’t require any parameter but returns a string value. It is also one of the extensively used commands for verification of messages, labels, errors etc displayed on the web pages.

Syntax :

What is the difference between “/” and “//” in Xpath?

Single Slash “/” –
Single slash is used to create Xpath with absolute path i.e. the xpath would be created to start selection from the document node/start node.

Double Slash “//” –
Double slash is used to create Xpath with relative path i.e. the xpath would be created to start selection from anywhere within the document.

How to select value in a dropdown?

Value in the drop down can be selected using WebDriver’s Select class.

Syntax:

What are the different types of navigation commands?

Following are the navigation commands:

navigate().back() – The above command requires no parameters and takes back the user to the previous webpage in the web browser’s history.

Sample code :

What is Same origin policy and how it can be handled?

The problem of same origin policy disallows to access the DOM of a document from an origin that is different from the origin we are trying to access the document.

Origin is a sequential combination of scheme, host and port of the URL. For example, for a URL http://www.softwaretestinghelp.com/resources/, the origin is a combination of http, softwaretestinghelp.com, 80 correspondingly.

Thus the Selenium Core (JavaScript Program) cannot access the elements from an origin that is different from where it was launched. For Example, if I have launched the JavaScript Program from “http://www.softwaretestinghelp.com”, then I would be able to access the pages within the same domain such as “http://www.softwaretestinghelp.com/resources” or “http://www.softwaretestinghelp.com/istqb-free-updates/”. The other domains like google.com, seleniumhq.org would no more be accessible.

So, In order to handle same origin policy, Selenium Remote Control was introduced.

How to click on a hyper link using linkText?

driver.findElement(By.linkText(“Google”)).click();

The command finds the element using link text and then click on that element and thus the user would be re-directed to the corresponding page.

The above mentioned link can also be accessed by using the following command.

driver.findElement(By.partialLinkText(“Goo”)).click();

The above command find the element based on the substring of the link provided in the parenthesis and thus partialLinkText() finds the web element with the specified substring and then clicks on it.

How to handle frame in WebDriver?

An inline frame acronym as iframe is used to insert another document with in the current HTML document or simply a web page into a web page by enabling nesting.

Select iframe by id:

When do we use findElement() and findElements()?

findElement() is used to find the first element in the current web page matching to the specified locator value. Take a note that only first matching element would be fetched.

Syntax :

How to find more than one web element in the list?

At times, we may come across elements of same type like multiple hyperlinks, images etc arranged in an ordered or unordered list. Thus, it makes absolute sense to deal with such elements by a single piece of code and this can be done using WebElement List.

Sample Code :

What is the difference between driver.close() and driver.quit command?

close() : WebDriver’s close() method closes the web browser window that the user is currently working on or we can also say the window that is being currently accessed by the WebDriver. The command neither requires any parameter nor does is return any value.

quit() : Unlike close() method, quit() method closes down all the windows that the program has opened. Same as close() method, the command neither requires any parameter nor does is return any value.