JavaScript Tips and Tricks for Efficient Coding

nearSea Technologies


JavaScript is a high-level programming language that has gained popularity among developers since its development in 1995. Its usage extends beyond traditional internet roles, making it a versatile language to learn. JavaScript is widely used for smart televisions, the internet of things (IoT), native apps for iOS and Android, and cross-platform desktop apps. In this article, we will explore some useful tips and tricks for efficient JavaScript coding.

1. Passing arguments as objects

Instead of passing parameters in a specific order, you can pass them as an object. This approach improves the readability of your code and makes it easier to manage. Using this technique eliminates the need to repeatedly check the function definition, and auto-completion becomes easier. It also helps to communicate the function's intent more clearly as function calls specify the value of each property.

2. Use the optional chaining operator

The optional chaining operator makes it easier to compare against undefined values. It allows you to use expressions with bracket notation and to stack optional chaining operators to check for deeper properties. This operator helps to improve code readability and makes it less prone to errors.

3. Using generators to create sequential IDs

Generators are functions that employ lazy evaluation by making use of the yield keyword to process and return data, on demand. It may look like generator functions will burn CPU cycles in an infinite loop; however, generators describe a state machine, allowing transitions to forward states to occur through provided code. These transitions occur on-demand whenever the next method is called, hence the term lazy evaluation. One practical use of generators is to create sequential IDs.

4. Use the spread operator to shallow copy objects

The spread operator is a one-liner that helps to concatenate arrays or merge objects instead of iterating over each instance manually. It is especially useful when performing state management in React or React Native.

5. Remove duplicates from arrays using Set

This trick treats some of JavaScript’s weird equality behaviours and works with values of any type. You can also use sets to remove duplicates from arrays of complex objects.

6. Casting values in arrays using map

This tip presents a very elegant solution for casting an array of numerical values represented as strings into JavaScript numbers. It leverages the map method of the Array and, passing Number as the parameter, calls the constructor of Number for each value in the array and returns the result.

7. Time the execution of your code

The time method takes a timer name as a parameter and expects to be met with a call to timeEnd, in which the same timer name is supplied. The timeEnd method prints the elapsed time in milliseconds between the two function calls.

8. Truncate an array using length

Truncating an array is easy by specifying the desired length. The array will be truncated with the sequence of that specific length that you set.

9. Use a switch/case statement instead of a series of if/else

Using a switch/case statement is faster when there are more than two cases, and it is more elegant. Avoid using it when you have more than ten cases.

10. Convert to floating number without killing performance

To convert a value to a floating number without killing performance, instead of using math.floor, math.ceil, and math.round, use "~~" to eliminate decimals.

11. Use Array Filter

This trick helps to filter out a bucket of elements from an array pool. This method creates an array filled with all array elements that pass a test provided as a function. According to the requirement, create a callback function for non-required elements.

12. Use a code beautifier

One of the most important aspects of writing beautiful code is formatting. A well-formatted code is easier to read, understand and maintain. To ensure that your code is well-formatted, use a code beautifier. JSLint is a popular code beautifier that checks your code for potential errors and formatting issues. Minification (JSMin, for example) is another technique that can help improve the performance of your JavaScript code by reducing its file size.

13. Cache your variables

Caching your variables can tremendously increase the performance of your JavaScript code. When using document.getElementById() or getElementsByClassName(), JavaScript has to travel through all elements repeatedly upon each similar element request. To avoid this unnecessary repetition and boost performance, cache your selections to a variable.


The tips and tricks highlighted in this article are useful for optimizing JavaScript code and improving its performance. From using the optional chaining operator and switch/case statements to caching variables and using generators, these techniques can significantly improve the efficiency of your code. By adopting these tips and tricks, developers can write more efficient, readable, and maintainable JavaScript code.