Over the last few years, JavaScript has become the scripting language of the Web: nearly every personal computer has and uses at least one JavaScript interpreter, and JavaScript is a major tool for building powerful web applications. With this popularity, it seems pretty easy to hire JavaScript developer both onshore and offshore. But the trick is that while almost any developer can use JavaScript for small tasks, not everyone understands it in its fullest and can use all the possibilities it offers.
With an offshore JavaScript developer, it can be more difficult to assess the depth of their knowledge and their experience with JavaScript, but the right JavaScript interview questions can help. So, here are some must-ask questions for a JavaScript developer interview.
Most coders avoid using global variables, because the code that depends on them can be difficult to test and maintain. They are also averse to naming conflicts with local variables. Globals are variables, available throughout the code, so they have no scope, whereas local variables scope is restricted to where it is declared.
JavaScript has a unique inheritance model, different from the classic ones in C# or Java, and it can be more flexible than those. Its inheritance is prototypal, JavaScript has only one construct - objects, which has an external link to another object, called its prototype. That one has its own prototype and so on, until an object is reached with null, which is the final link in the prototype chain.
The answer you expect to get here is that the candidate builds reusable code, using module pattern or class inheritance, because these approaches will let multiple developers work on one project easily. Plus, it’s easier to test classes or modular code.
“This” keyword points to the object currently in scope, which owns where you are in the code. For example, if you are in an object created with a new keyword, “this” will refer to the object that is being created.
JavaScript is a loosely-typed language, which means that when variables are created, no type declarations are required. JavaScript determines what the type should be itself and supports the following types: Function, Null, Object, String, Number, Boolean, and Undefined.
This, of course, is an open-ended question that will help you see how the candidate feels about open source, whether they stay informed about the new technology options in their field, how they make choices on what frameworks to use, and so on.
JavaScript has a lot of potential for web development, and a good offshore JavaScript developer will use everything JavaScript has to offer for the benefit of your product. Use these JavaScript interview questions to help you hire the best remote JavaScript developer!
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