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Common JavaScript Mistakes That You Should Avoid

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Common JavaScript Mistakes That You Should Avoid

Don't get caught up making mistakes while using JavaScript. Here is a quick cheat sheet to reference before beginning your next JS project.

· Web Dev Zone
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JavaScript is the client-side programming language that is used to develop interactive pages for the client. Being a client-side programming language, it helps the website to load faster, limiting the load on a site. The still page has now become history soon after the introduction of JavaScript in the field of web designing. It delivers interactive UI (user Interface) that boosts the UX (User Experience) without adding extra load on the server.

Most of you who are either a learner or a professional coder of JavaScript scripts get into the trap of some common mistakes. There are some pitfalls that a coder must avoid while writing different sorts of scripts via a client-side scripting language.

Memory Leaks:  Memory leaks can be terms as the memory that is not used by the application anymore and still not returned back to the pool of free memory. Different languages have different memory management system that helps them to heed the garbage memory.

Generally, it is a common problem that most of the developers don’t have an idea that, memory management can be handled on developers end. While writing the code, the developer can inform the program whether the value is occupied or is free. If you are creating a web application for a university comparison website or a limited company with quality formations then you should work carefully on Javascript.

JavaScript is one of the garbage collected languages.  Garbage collected languages are those which allows the developer to manage its memory, resulting in effective memory management.

In JavaScript, the garbage collection is done in form of “roots”. These roots are the global variables which are used to store the references within the code. Mark and Sweep algorithm is used to control the memory. The algorithm marks the roots that are being used, as active.

Simultaneously, the roots which are left inactive will be available for use again.

If Else Error: This concept is used when you want the program to respond to every occurrence of the answer. Like for example, “==” and “=” are to misconceptions that developers normally find.

These types of typo errors must be avoided prior to moving on the final coding section. Generally, these types of test can arrive on social media.

JavaScript Closure:  Closure in JavaScript is defined as the nested function that uses the parent function’s variable. It can also be defined as the function in which has the command on three types of variables i.e.

  • A variable declared within the function
  • A variable declared in the parent function
  • A global variable that is accessible to all

To deal with these issues, the developers are generally prescribed to avoid making unnecessary nested functions. Solving this issue will not only make your code closure free, but it will also deal with the memory allocation problem.

Whenever you are creating a new object or class, always consider associating the methods with the object's prototype instead of defining it in the object’s constructor.

Undefined vs NULL: Well, this issue occurs with the newcomers who don’t know the difference between the undefined and NULL value. In other programming languages, it is easy to set NULL value to the variables. However, in JavaScript, by default, the variables are set to undefined and objects are set to NULL. For an object to be NULL, it must be initially defined by the coder.

Following are some points that you must be aware of:

undefined == null //true

undefined === null //false

typeof null //”object” should have returned null. If it’s an object, what about adding few properties

typeof undefined //”undefined”

The above-mentioned bugs are a few that a JS developer generally neglects while coding for a script. These issues seem to be minor, but it causes a big loss of your memory, code structure. It also generates loopholes that make it easy to breach the code.

So, next time you write a script of code, always remember the points mentioned above. Remember that these are not the only mistakes that a code does. Instead, there are many other which should be avoided to get a bug free script. 

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Topics:
javascript ,tips ,web dev

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