18 JavaScript Tips : You Should Know for Clean and Efficient Code

In this post, I’ll share 18 JavaScript tips, with examples that you should know for writing clean and efficient code.

Let’s get started!🚀

Arrow Function

You can use arrow functions to simplify function declarations.

For example:

function add(a, b) {
  return a + b;
}

// Arrow function
const add = (a, b) => a + b;

Array.from()

The Array.from() method can be used to convert any iterable objects into arrays.

const str = "Hello!";
const arr = Array.from(str);

console.log(arr); //Output: ['H', 'e', 'l', 'l', 'o', '!']

Display Data with console.table()

If you want your data organized or in tabular format in the console, then you can use console.table().

const person = {
    name: 'John', 
    age: 25,
    profession: 'Programmer'
}
console.table(person);

Output:

Use const and let efficiently

Use const for variables that won’t be reassigned and let for those that will, for better code organization.

const PI = 3.14;
let timer = 0;

Extract Object Properties with Destructuring

By using destructuring to extract properties from objects, you can enhance code readability.

const person = {
    name: 'John', 
    age: 25,
    profession: 'Programmer'
}

//Instead of this 👇
console.log(person.name);
console.log(person.age);

//Use this👇
const {name, age} = person;
console.log(name);
console.log(age);

Set Default Values with Logical OR Operator

Set default values easily using the || operator.

function greet(name) {
  name = name || 'Person';
  console.log(`Hello, ${name}!`);
}

greet(); //Output: Hello, Person!
greet("John"); //Output: Hello, John!

Effortlessly Empty an Array

You can empty an array easily by using the length property.

For example:

let numbers = [1, 2, 3, 4];
numbers.length = 0;
console.log(numbers); //Output: []

JSON.parse()

Use JSON.parse() to convert a JSON string into a JavaScript object, this ensures seamless data manipulation.

const jsonStr = '{"name": "John", "age": 25}';
const person = JSON.parse(jsonStr);
console.log(person); 
//Output: {name: 'John', age: 25}

Map() Function

Use the map() function to transform elements in a new array without modifying the original array.

For example:

const numbers = [1, 2, 3, 4];
const doubled = numbers.map(num => num * 2);
console.log(numbers); //Output: [1, 2, 3, 4]
console.log(doubled); //Output: [2, 4, 6, 8]

Object.seal()

You can use Object.seal() method to prevent adding or removing properties in the object.

const person = {
    name: 'John', 
    age: 25
};
Object.seal(person);
person.profession = "Programmer";
console.log(person); //Output: {name: 'John', age: 25}

Object.freeze()

You can use Object.freeze() method to prevent any changes to an object, including adding, modifying or deleting properties.

const person = {
    name: 'John', 
    age: 25
};
Object.freeze(person);
person.name = "Mark";
console.log(person); //Output: {name: 'John', age: 25}

Remove Array Duplicates

You can remove duplicate elements from an array using Set.

const arrWithDuplicates = [1, 12, 2, 13, 4, 4, 13];
const arrWithoutDuplicates = [...new Set(arrWithDuplicates)];
console.log(arrWithoutDuplicates); 
//Output: [1, 12, 2, 13, 4]

Swap values using Destructuring

You can swap two variables easily using destructuring.

For example:

let x = 7, y = 13;
[x, y] = [y, x];
console.log(x); //13

Spread Operator

You can copy or merge arrays efficiently using the spread operator.

For example:

const arr1 = [1, 2, 3];
const arr2 = [9, 8, 7];

const arr3 = [...arr2];
const mergedArr = [...arr1, ...arr2];

console.log(arr3); //[9, 8, 7]
console.log(mergedArr); //[1, 2, 3, 9, 8, 7]

Template Interpolation

Utilize template literals for string interpolation and enhanced code readability.

For example:

const name = 'John';
const message = `Hello, ${name}!`;

Ternary Operator

You can simplify conditional statements with the ternary operator.

const age = 20;

//Instead of this👇
if(age>=18){
    console.log("You can drive");
}else{
    console.log("You cannot drive");
}

//Use this👇
age >= 18 ? console.log("You can drive") : console.log("You cannot drive");

Use === Instead of ==

Prevent type coercion issues by using strict equality (===) instead of loose equality (==).

const num1 = 5; 
const num2 = '5'; 

// Instead of using == 
if (num1 == num2) { 
	console.log('True'); 
} else { 
	console.log('False'); 
} 

// Use === 
if (num1 === num2) { 
	console.log('True'); 
} else { 
	console.log('False'); 
} 

Use Descriptive Variable and Function Names

Use meaningful and descriptive names for variables and functions to enhance code readability and maintainability.

// Don't declare variable like this
const a = 18;

// use descriptive names
const numberOfTips = 18;

That’s all for today!

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