TypeScript developers are in high demand.
TypeScript is a programming language used to build web and mobile apps. As a result, many companies are looking to hire TypeScript developers.
However, with so many companies trying to build the best web and mobile apps using TypeScript, hiring devs is difficult. What’s more, making the wrong hire could cost your company thousands of dollars.
So if you want to hire the best TypeScript developers, you must craft a compelling job description. Then, you need to test the skills and knowledge of the developers who apply to see whether they can meet your demands.
These common TypeScript interview questions can help you learn more about each candidate’s coding background and test these skills. You’ll get to know your developers thoroughly, and you can dig into their applications.
But what questions should you ask?
Aside from the standard questions like “What have you accomplished?” and “What are your strengths?”, you’ll want to assess your candidate’s knowledge of TypeScript.
And in this blog, you’ll find common TypeScript interview questions to help you do this.
Let’s go!
Common TypeScript interview questions
Q: What is TypeScript and what can it do?
TypeScript is an open-source programming language which acts as a statically typed superset of JavaScript. Extending JavaScript with type annotations and interfaces helps developers catch errors during compilation rather than runtime, making code more efficient.
TypeScript is also highly scalable, which means it’s possible to develop large apps using features like namespaces, decorators, and abstract classes. One of TypeScript’s greatest strengths is its seamless integration with the JavaScript ecosystem and modern frameworks like Angular, React, or Vue.js. This makes it an invaluable tool for any developer looking to create maintainable and robust web apps.
Q: What are Modules in TypeScript?
Modules help to organize and contain code, making it easier to develop, maintain, and test large apps. They allow you to split your code into separate files, keeping each file focused on a specific functionality or a single responsibility. Modules manage dependencies and avoid naming conflicts by using distinct namespaces and imports/exports.
There are two main types of modules in TypeScript:
External modules (aka “file modules”): External modules are one module per source file. When you create a new TypeScript file and work with the import and export keywords, you’re automatically creating an external module. These are the most commonly used TypeScript modules.
Ambient modules: These provide type information for third-party libraries or existing global variables. They’re typically declared using a .d.ts file and may be provided by the library developers themselves or created by the community. The declare module syntax is used to define an ambient module.
Q: Why choose TypeScript over JavaScript?
TypeScript has the edge over JavaScript for a few reasons. One of the most noticeable benefits of TypeScript is the tools and IDEs. These provide a rich environment that helps to find errors quickly. Some other benefits include:
Advanced auto completion and IntelliSense: TypeScript provides enhanced auto completion, code navigation, and refactoring capabilities through better integration with editors like Visual Studio Code. These capabilities make the development process faster and more efficient.
Large-scale application support: Features like classes, interfaces, generics, and namespaces in TypeScript facilitate the design of modular code. These features make it well-suited for building large and complex apps.
Improved code readability: TypeScript’s type annotations and advanced OOP features bring clarity to codebases and make it easier to understand, debug, and maintain code written by other developers.
Strict null checks: TypeScript enforces strict null checks, which can help catch null or undefined values during compilation. This reduces runtime errors related to missing or inaccessible data.
Q: Do TypeScript files need compilation?
Browsers can’t interpret TypeScript, so compiling is needed to convert TypeScript to JavaScript. For compilation, you need the TypeScript compiler.
TypeScript has all the features and functionality of JavaScript, with some added features. It improves developer experience, provides features like type aliases, abstract classes, tuples, generics, etc., and allows developers to add type safety to their projects.
Q: What are the benefits of using TypeScript?
TypeScript offers lots of benefits that improve code quality and streamline collaboration. Some of these benefits include:
Static typing: TypeScript adds static typing to JavaScript, which catches type-related errors at compile-time instead of runtime. This allows developers to identify and fix issues early in the development process, reducing bugs and improving overall code quality.
Code maintainability: TypeScript’s static types, interfaces, and other OOP features contribute to better code readability and maintainability, making it easier for developers to understand and work with shared codebases.
Better tooling and editor support: TypeScript provides excellent integration with popular IDEs, resulting in advanced autocompletion, code navigation, and refactoring tools. This improves the development experience and boosts productivity.
Large-scale application support: TypeScript’s features, such as generics, namespaces, and modules, foster the creation of modular and scalable code, making it an ideal choice for large and complex applications.
JavaScript ecosystem compatibility: TypeScript is fully compatible with JavaScript libraries, frameworks, and tools, enabling seamless integration into existing development workflows.
Q: How can you use class constants in TypeScript?
You can declare class constants in TypeScript using the keywords “read-only”, const, and read-only static.
The read-only keyword marks a property as unchangeable; you cannot change its value once set.
Const keyword declares a constant outside the class and uses it inside the class. But if you want it to be accessible only inside the class, declare it privately.
Q: What are Getters/Setters in TypeScript?
In TypeScript, getters and setters are special class methods used to control the access and modification of object properties. They provide a flexible and encapsulated way to work with properties while allowing you to add additional logic around retrieval and assignment.
Getters are accessor methods used to retrieve the value of a property. They are defined using the get keyword followed by the method name and have no parameters. Getters are accessed like regular properties but invoke the getter function internally to compute the result.
Setters, the accessor methods used to update the value of a property, are a developer’s best friend. They’re defined using the set keyword followed by the method name and contain a single parameter representing the new value. Setters are assigned values like regular properties, but they invoke the setter function internally to perform additional logic, making your code more robust and reliable.
Meet available, vetted talent today!
So these common TypeScript interview questions should help you hire a TypeScript developer or two for your company.
But would you like help with this hiring process?
Whether you’re looking for temporary help or your next full-time developer, let Gun.io help you find the right person for the job. We’ve helped hundreds of companies – from Fortune 500s to start ups – hire world-class talent.
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