Preparing for a Walmart JavaScript interview can be a critical step towards securing a role in one of the largest retail companies in the world. JavaScript plays a vital role in the development of dynamic, responsive, and high-performing web applications at Walmart. Whether you’re applying for a front-end developer or full-stack role, mastering JavaScript concepts is essential.
This blog is designed to help you navigate the common interview questions related to JavaScript, ranging from basic to advanced topics. You’ll encounter questions that test your knowledge of core JavaScript principles like closures, promises, and the event loop, as well as your ability to work with the DOM and optimize web performance. By understanding these topics and practicing sample questions, you’ll be well-equipped to showcase your JavaScript expertise and increase your chances of success in the Walmart interview process.
Walmart Inc. is a global retail powerhouse and one of the largest companies in the world by revenue. Founded in 1962 by Sam Walton, Walmart started as a single store in Rogers, Arkansas, with a vision to offer customers affordable prices and great value. Over the years, the company has expanded its footprint to become an international retail giant with operations spanning more than 20 countries and over 10,000 stores worldwide, including in the U.S., Canada, Mexico, Chile, China, and India.
Retail and E-Commerce Leadership:
Walmart’s core business is retail, and it offers a diverse range of products such as groceries, apparel, electronics, furniture, and home goods. The company’s stores are divided into three main categories: Walmart Supercenters (large stores that offer a full range of groceries and general merchandise), Walmart Discount Stores (focused on general merchandise), and Walmart Neighborhood Markets (smaller stores with a focus on groceries). Walmart also operates Sam’s Club, a membership-based warehouse club that provides bulk goods and exclusive deals.
Why Join in Walmart?
Joining Walmart as a JavaScript developer offers unique opportunities to work for one of the world’s largest and most innovative retail companies. Here are several compelling reasons to consider a career with Walmart:
1. Work on Cutting-Edge Technologies
Walmart is at the forefront of digital transformation in the retail industry, embracing the latest technologies to enhance customer experiences and optimize operations. As a JavaScript developer, you’ll have the chance to work with modern tools and frameworks, including React, Node.js, and Angular, to develop innovative web applications and features.
2. Impact Millions of Users
With millions of customers using Walmart’s website and mobile apps every day, your work as a JavaScript developer will have a direct impact on their shopping experience. You’ll be building high-performance, scalable applications that improve customer engagement and streamline transactions.
3. Collaborate in a Dynamic, Cross-Functional Team
At Walmart, you’ll have the chance to collaborate with a diverse and talented team of developers, designers, product managers, and data scientists. The company fosters a collaborative and inclusive work culture, where your ideas and contributions are valued.
4. Focus on Innovation and Problem-Solving
Walmart thrives on innovation. As a JavaScript developer, you’ll be encouraged to think creatively and solve complex problems. Whether it’s improving the performance of the website, optimizing the user interface, or integrating advanced technologies like AI, there will always be new challenges to keep you engaged.
5. Career Growth and Learning Opportunities
Walmart places a strong emphasis on employee growth and development. As a JavaScript developer, you’ll have access to extensive learning resources, workshops, and mentorship programs to continuously enhance your technical skills. Whether you want to specialize in front-end, back-end, or full-stack development, Walmart provides the tools and support you need to grow in your career. The company also offers internal career mobility, allowing you to explore different roles or even switch between departments as you progress.
6. Competitive Compensation and Benefits
Walmart offers competitive salary packages, which often include bonuses and stock options. The company also provides a comprehensive benefits package, including health insurance, retirement savings plans, paid time off, and employee discounts.
7. Work on a Large-Scale E-Commerce Platform
Walmart is one of the biggest players in the e-commerce space, competing with giants like Amazon. As a JavaScript developer, you will be working on a highly scalable platform that handles millions of transactions daily.
8. Focus on Sustainability and Social Responsibility
Walmart is committed to creating a positive impact on the environment and communities. As a company, it strives to achieve sustainability goals, reduce waste, and ensure ethical sourcing of products. Working for Walmart means you’re part of a team that values corporate social responsibility and takes steps to contribute to a better world.
9. Flexible Work Environment
Walmart embraces flexible working arrangements, offering options for remote work or hybrid schedules, depending on the position. This flexibility allows you to maintain a healthy work-life balance while still making significant contributions to the company’s goals. I
10. Global Impact and Career Mobility
Walmart’s vast global presence gives you the chance to work on projects with international scope, allowing you to experience the challenges of developing for diverse markets. With career opportunities across different regions and departments, you can continue to grow within the company while exploring various facets of technology and business.
Top Walmart Javascript Interview Questions and Answers
Here’s a list of JavaScript interview questions along with detailed answers that can help you prepare for interviews:
1. What are the different data types present in JavaScript?
Answer: JavaScript has 7 primitive data types:
Number
String
Boolean
Undefined
Null
Symbol (added in ES6)
BigInt (added in ES11)
Additionally, JavaScript has a non-primitive Object type, which includes arrays, functions, and objects.
2. What is the difference between == and === in JavaScript?
Answer:
== (loose equality) compares values after converting them to the same type (type coercion).
=== (strict equality) compares both values and types without type coercion.
Example:
0 == '0' is true
0 === '0' is false
3. What is hoisting in JavaScript?
Answer: Hoisting is JavaScript’s default behavior of moving all declarations (var, function, let, const) to the top of their scope during the compile phase, before the code is executed.
Variables declared with var are hoisted and initialized with undefined.
Variables declared with let and const are hoisted but are not initialized, leading to a “temporal dead zone.”
4. What is the difference between null and undefined in JavaScript?
Answer:
null is an assignment value that represents no value or no object.
undefined means a variable has been declared but not assigned any value.
5. What is closure in JavaScript?
Answer: A closure is a function that “remembers” its lexical scope, even when the function is executed outside that scope. This allows for private variables and functions in JavaScript.
Answer: Event delegation is a technique where a single event listener is attached to a parent element rather than multiple listeners on individual child elements. The event bubbles up from the child to the parent, where it is caught.
Answer: A promise is an object representing the eventual completion (or failure) of an asynchronous operation. It has three states:
Pending
Fulfilled
Rejected
Example:
const myPromise = newPromise((resolve, reject) => { let success = true; if (success) resolve("Task completed"); elsereject("Task failed");
});myPromise.then(result =>console.log(result)).catch(error =>console.log(error));
8. What is the difference between let, var, and const?
Answer:
var: Function-scoped or globally-scoped, can be re-declared and updated.
let: Block-scoped, can be updated but not re-declared within the same scope.
const: Block-scoped, cannot be updated or re-declared. However, objects and arrays assigned to const can be modified.
9. What is the purpose of the bind() method in JavaScript?
Answer: The bind() method creates a new function that, when called, has its this keyword set to the provided value, and can optionally be pre-configured with arguments.
10. What is the difference between call() and apply() in JavaScript?
Answer: Both call() and apply() are used to invoke a function with a specific this value and arguments:
call() accepts arguments one by one.
apply() accepts arguments as an array.
Example:
functionintroduce(name, age) { console.log(`I am ${name} and I am ${age} years old.`);
}
introduce.call(null, 'Alice', 25); // call
introduce.apply(null, ['Alice', 25]); // apply
11. What is the this keyword in JavaScript?
Answer: The this keyword refers to the context in which a function is called. Its value is determined by how a function is invoked:
In a method, this refers to the object the method is called on.
In a regular function, this refers to the global object (window in browsers).
In arrow functions, this is lexically bound to the surrounding context.
12. What is the event loop in JavaScript?
Answer: The event loop is a mechanism that allows JavaScript to handle asynchronous operations like I/O, timers, etc. It constantly checks the call stack and message queue to ensure that code execution happens in the correct order.
13. What are higher-order functions in JavaScript?
Answer: Higher-order functions are functions that take other functions as arguments or return functions as their result. Examples include map(), filter(), and reduce().
14. What is the difference between synchronous and asynchronous code?
Answer:
Synchronous code runs sequentially, blocking the next task until the current one finishes.
Asynchronous code allows tasks to run in parallel, enabling the execution of other tasks while waiting for a task to complete (e.g., using callbacks, promises, async/await).
15. Explain the concept of the prototype in JavaScript.
Answer: Every JavaScript object has an internal property called prototype. It is used to share properties and methods between objects. When you try to access a property or method, JavaScript will look at the object itself first and then in its prototype chain.
16. What is an IIFE (Immediately Invoked Function Expression)?
Answer: An IIFE is a function that is defined and executed immediately after its creation. It’s often used to create a private scope.
Example:
(function() { console.log('I am an IIFE!');
})();
17. What is destructuring in JavaScript?
Answer: Destructuring allows you to unpack values from arrays or properties from objects into distinct variables.
Answer: Arrow functions provide a shorter syntax for writing functions and do not have their own this context, instead, they inherit this from the surrounding lexical scope.
21. Explain the concept of setTimeout() and setInterval() in JavaScript.
Answer:
setTimeout(callback, delay): Executes the callback function once after the specified delay.
setInterval(callback, interval): Executes the callback function repeatedly at the specified interval.
Example:
setTimeout(() =>console.log('This runs after 2 seconds'), 2000); setInterval(() =>console.log('This runs every 2 seconds'), 2000);
22. What is an asynchronous function in JavaScript?
Answer: An asynchronous function is a function that performs asynchronous operations using async and await. It returns a promise and allows you to write asynchronous code in a more readable, synchronous-like manner.
Example:
asyncfunctionfetchData() { let response = awaitfetch('https://example.com'); let data = await response.json(); return data;
}
23. What is the difference between apply() and bind()?
Answer: Both methods set the value of this:
apply() calls the function immediately with arguments passed as an array.
bind() returns a new function, allowing you to set this and arguments, but does not invoke the function immediately.
24. Explain the concept of modules in JavaScript.
Answer: Modules allow code to be divided into separate files, promoting better organization and maintainability. ES6 introduced the import and export keywords for handling modules.
Example:
// Exporting a function exportfunctiongreet() { console.log('Hello!');
}// Importing the function in another file import { greet } from‘./greet.js’; greet();
25. What are Map and Set in JavaScript?
Answer:
Map: A collection of key-value pairs, where keys can be any data type.
Set: A collection of unique values, with no duplicates.
Example:
const map = newMap();
map.set('key', 'value');const set = newSet();
26. What is the JSON.parse() and JSON.stringify() in JavaScript?
Answer:
JSON.parse(): Converts a JSON string into an object.
JSON.stringify(): Converts an object into a JSON string.
Answer: Regular expressions are patterns used to match character combinations in strings. They are often used for validating input, searching, and replacing text.
35. What is setImmediate() in Node.js?
Answer:setImmediate() is a Node.js function used to execute a callback after the current event loop cycle.
Walmart Javascript Technical Interview Questions and Answers
1: Which of the following is a JavaScript framework/library?
2: What is the purpose of CSS in web development?
3: What does CRUD stand for in web development?
4: Which of the following is a popular CSS framework?
5: Which technology is commonly used for asynchronous communication between the client and server?
Ever wondered how much you really know? It's time to put your brain to the test!
1. What are the different data types in JavaScript?
Answer: JavaScript has several data types:
Primitive types: Number, String, Boolean, Null, Undefined, Symbol, and BigInt.
Reference types: Object (which includes Array, Function, Date, etc.).
2. Explain the difference between let, var, and const.
Answer:
var: Function-scoped, can be redeclared and updated, hoisted but initialized as undefined.
let: Block-scoped, cannot be redeclared but can be updated, hoisted but not initialized.
const: Block-scoped, cannot be redeclared or updated, value must be assigned at declaration.
3. What is the difference between == and === in JavaScript?
Answer:
==: Compares values for equality, allowing type coercion. For example, 5 == '5' returns true.
===: Strict equality, compares both value and type. For example, 5 === '5' returns false.
4. What are closures in JavaScript?
Answer: A closure is a function that retains access to its lexical scope even when the function is executed outside that scope. This allows it to access variables defined in the outer function after the outer function has returned.
Answer: Event delegation is a technique where a single event listener is attached to a parent element to manage events for multiple child elements. It utilizes event bubbling to capture events from child elements and handle them using the parent element’s event listener.
document.querySelector('#parent').addEventListener('click', function(event) { if (event.target.matches('.child')) { console.log('Child clicked');
}
});
6. Explain the concept of prototypal inheritance.
Answer: JavaScript uses prototypal inheritance to allow objects to inherit properties and methods from other objects. Every JavaScript object has a prototype property that refers to its prototype, and methods or properties defined on the prototype are shared among instances.
const person1 = newPerson(‘John’);
person1.greet(); // Hello, John
7. What are promises in JavaScript, and how do you use them?
Answer: Promises in JavaScript represent the eventual completion (or failure) of an asynchronous operation. A promise can be in one of three states: pending, fulfilled, or rejected.
Answer: The async keyword is used to define a function that returns a promise. The await keyword can only be used inside async functions, and it pauses the execution of the function until the promise is resolved.
asyncfunctionfetchData() { let response = awaitfetch('https://api.example.com/data'); let data = await response.json(); console.log(data);
}fetchData();
10. What is the this keyword in JavaScript?
Answer: The this keyword refers to the object in which the function is executed:
In a method: refers to the object that owns the method.
In a function: refers to the global object (in non-strict mode).
In strict mode: remains undefined in regular functions but behaves normally in arrow functions.
