10 Advanced JavaScript Tricks for Experienced Developers

November 24, 2023 123 Views

JavaScript is unarguably the most used programming language in the realm of web development. Back in the day, web pages or web applications used to be static. But thanks to JavaScript, we can now create dynamic websites and add all sorts of interactive elements, from buttons and dropdown menus to interactive charts, graphs, and maps. Various JS frameworks that speed up and ease the web development process are also available today, making JavaScript one of the most popular programming languages.

While JavaScript is easy to learn, it’s a dynamic and versatile language that is constantly evolving. Thus, new features and functionalities are regularly added to the language. This gives rise to new and advanced JS techniques. Moreover, with the emergence of JavaScript frameworks, such as React JS framework, Ext JS JavaScript framework, etc., developers are discovering new JS techniques and patterns to optimize the performance of their web apps. If you’re a web developer, even an experienced one, learning advanced JS tricks and techniques can be a game-changer. They can help you write cleaner and more maintainable code and create faster, better, more responsive web applications.

This article will explore ten advanced JavaScript tricks and techniques that you might not know, even if you’re an experienced web developer. When implemented correctly, these techniques can transform the way you create web applications.

1. Leveraging Object Destructuring for Efficient Coding

JS frameworks - coding

Object destructuring is a handy JavaScript technique that enables developers to write more clean, concise and readable code. It basically simplifies the way we extract values from arrays and objects and assign them to variables.

Here is an example code demonstrating how object destructing can help simplify code:

// Without object destructuring
const employee = { name: 'Gary', age: 28 };
const name = employee.name;
const age = employee.age;

// With object destructuring
const { name, age } = employee;
console.log(name); // Output: Gary
console.log(age);  // Output: 28

Notice how object restructuring minimizes redundancy and provides a more compact and readable syntax for assigning object properties to variables.

JavaScript also allows you to provide default values for variables during object destructuring when the corresponding property in the object is undefined. This way, you can ensure your code doesn’t break. Moreover, you can destructure nested objects as well. In other words, you can destructure an object’s properties even if the object is a property of some other object.

Here is an example code demonstrating nested object destructuring:

const employee = {
  name: 'Gary',
  age: 28,
  address: {
    city: 'xyz city',
  }
};
// Nested object destructuring
const { name, age, address: { city } } = employee;
console.log(name); // Output: Gary
console.log(city); // Output: xyz city

2. Mastering the Spread and Rest Operators

Developers often confuse the spread and rest operators as the same thing because both operators use the same syntax, that is, three dots(…). However, they serve different purposes and are used in different contexts.

The spread operator is typically used for expanding arrays, object properties, etc. For instance, you can use a spread operator to spread the individual elements of an array whenever needed. Thus, you can use it to copy elements of one array into another array.

const arrayA = [2, 2, 3];
const arrayB = [4, 7, 8];
const newArray = [...arrayA, ...arrayB];
// Output: [2, 2, 3, 4, 7, 8]

Similarly, you can use a spread operator in objects to combine the properties of two or more objects.

The rest operator is mainly used in function parameters and object or array destructuring. For example, you can use the rest operator to enable a function to handle an indefinite number of arguments. The function captures all these arguments neatly in an array, making them easy to handle.

function add(...numbers) {
  return numbers.reduce((acc, add) => acc + add, 0);
}
const result = add(1, 2, 3, 4, 5);
// Output: 15

We can also use a rest operator in array destructuring to collect the remaining elements of an array into a new array.

const num = [1, 2, 3, 4, 5];
const [first, ...rest] = num;
// first: 1, rest: [2, 3, 4, 5]

3. Implementing Memoization for Performance Optimization

best JavaScript framework - Two Women Looking at the Code at Laptop

Memoization is an efficient technique for optimizing the performance of functions in programming languages. It is especially helpful for functions that we need to call frequently with the same arguments or functions that require a lot of computational resources. With memorization, we can avoid redundant computations to improve the performance of functions. We basically store the results of computationally expensive and time-consuming functions and return cached results when the same input occurs instead of re-computing the function.

Also read: Choosing a JS framework for creating cross-platform apps.

4. Advanced Array Methods and Functional Programming

Using advanced array methods like ‘reduceRight’, ‘flatMap’, and ‘every’, you can achieve complex operations more efficiently.

reduceRight

The reduceRight array method allows you to process elements of an array in reverse order. For example, you can use it to concatenate nested arrays in reverse order:

const nestarrays = [[4,5], [6, 7], [8, 9]];

const flattenedReversed = nestarrays.reduceRight((acc, arr) => acc.concat(arr)[]);
// Output: [9, 8, 7, 6, 5, 4]

flatMap

With the flatMap method, you can map each element to an array and then flatten the results into a single array to eliminate the nested structure. Finally, we can map over the flattened result by using another function for every element of the flattened array.

Here is an example code using the ‘flatMap’ method:

const sentence = ['Hello world'];
const result = sentence
  .flatMap(sentence => sentence.split(' '))
  .map(word => word.toLowerCase()) //converting to lowercase
  .flatMap(word => word.split(''));

console.log(result);
// Output: ['h', 'e', 'l', 'l', 'o', 'w', 'o', 'r', 'l', 'd']

every

This is another useful method that allows us to test whether each element in an array passes a given function.

5. Promises and Async/Await Best Practices

Promises are a great JavaScript feature that allows us to handle asynchronous operations efficiently. They essentially represent a value that is currently available, will be available in the future, or will never be available. A Promise can either be pending, fulfilled or rejected.

However, using promises isn’t enough. We must also understand the concept of Async/Await to manage and handle asynchronous operations and errors more efficiently. Async/Await, when used with Promises, allows us to handle errors in a synchronous style within asynchronous code. Hence making the code simple and more readable. For instance, we can use ‘await’ with a Promise. If the Promise is rejected, we can catch the error using a try-catch block.

async function combinedExample() {
  try {
    const result = await fetchData(); // Using Async/Await with a Promise
    console.log(result);
  } catch (error) {
    console.error('An error occurred:', error);
  }
}

6. Pro Tips for Optimizing JavaScript Performance

Improving JavaScript code performance will make your web app more efficient and responsive. Some techniques to optimize your JavaScript code performance include optimizing loops, reducing DOM manipulations, and minimizing reflows. Here are some tips to implement these techniques:

Use ‘for’ loops instead of ‘while’ loops when the total number of iterations is definite to optimize loops.
Limit DOM updates or batch multiple DOM updates together to reduce unnecessary reflows and re-rendering. For instance, if you’re using the Ext JS front-end JavaScript framework, you can use the ‘batchLayout’ method to combine various updates into one operation for efficient code execution.
Minimize DOM access inside loops by caching the length of the loop outside the loop. This will help avoid re-evaluation of the loop in every iteration.
If you’re using a front-end framework like React or Vue, it’s best to utilize a virtual DOM/ virtual document object model. This helps reduce the number of actual DOM manipulations.
Limit DOM manipulations by leveraging techniques like throttle and debounce.

7. Advanced Closures and Scope Manipulation

JS frameworks - A women using Laptop for coding

Closures are a key concept in JS. They make it easier to maintain the code by allowing us to bundle the data/functionality into a single package. Moreover, they enable developers to create encapsulated, modular and private code in JS. For example, you can use closures to declare objects with private states and methods:

function counter() {
    let num = 0;
    return {
        increment: function() {
            num++;
        },
        getCount: function() {
            return num;
        }
    };/
}

const mycounter = counter();
mycounter.increment();
console.log(mycounter.getCount());

You can also create a private scope by wrapping your code in an IIFE. An IIFE is essentially a function expression that is executed right after it is defined or created.

8. Functional Composition and Currying Techniques

Functional composition is a useful technique that enables developers to combine multiple functions and produce a new function. In functional composition, the output of one function is the input of the other function. This allows developers to create and execute complex operations by combining various modular functions.

Currying is another optimization technique for function. It allows us to split a function containing several arguments into multiple functions, where each function has a single argument.

Functional composition and currying facilitate reusability by allowing us to create multiple small functions that we can easily combine or use partially as needed. This also makes the code more maintainable.

Also Read: 7 Best JS UI Widgets For Enterprise Web Apps

9. Leveraging Web Workers for Parallel Processing

Web Workers allow us to offload specific tasks to background threads, separating them from the main thread of the web app. When we offload resource-intensive computations to Web Workers, it prevents the blockage of the main thread. Hence, the main thread is readily available to respond to user interactions and inputs, making the UI more responsive. Web Workers also enable parallel processing and computing, enhancing the web app’s performance.

10. Exploring JavaScript Proxies for Advanced Object Manipulation

JavaScript Proxies are essentially objects that allow developers to customize operations on other objects. They basically serve as intermediaries between the target object and the code. For instance, you can use JavaScript proxies to define custom behavior for function invocation, property access, assignment, etc.

Moreover, JavaScript Proxies support virtual object creation, meta-programming, and validation. For instance, you can utilize JavaScript Proxies for meta-programming to customize the behavior of objects dynamically.

Conclusion

JavaScript is a popular and powerful programming language for creating interactive and responsive websites and web apps. With new functionalities and features added to the language regularly and the emergence of the best JavaScript frameworks, new and advanced JavaScript techniques are also emerging. This article explores ten advanced JavaScript tricks and techniques that advanced developers can implement to create faster, better, more responsive web applications.

Frequently Asked Questions (FAQ)

Are these tricks specific to certain JavaScript frameworks?

Most of these tips and techniques can be implemented on any web app built using JavaScript. However, some techniques are specific to certain JavaScript web frameworks. For example, virtual DOM is specific to React and Vue JS frameworks.

How challenging are these advanced techniques to implement?

Some techniques are easy to implement, while others involve some learning curve. However, learning the basics and core concepts behind these JavaScript techniques can make the implementation easy.

What are some of the best JavaScript libraries and JS frameworks?

Some of the most popular JavaScript frameworks include Ext JS, React and Vue. Ext JS is a popular JavaScript framework for creating web and mobile applications. The robust framework offers 140+ pre-built UI components and supports two-way data binding. React is an open-source JavaScript framework for creating interactive user interfaces and creating web apps.