- Use strict mode to enforce modern JavaScript syntax and catch errors early.
- Always declare variables with
const
orlet
, rather thanvar
. - Use arrow functions instead of
function
for cleaner and concise code. - Make use of destructuring to extract values from arrays and objects into variables.
- Use template literals for string concatenation and embedding expressions.
- Prefer
forEach
overfor
loop for simple iterations. - Make use of higher-order functions like
map
,filter
, andreduce
to process arrays. - Avoid using global variables and always use
const
orlet
to scope variables. - Use modules to organize your code and avoid naming collisions.
- Always initialize variables with default values to avoid
undefined
values.

Top 10 Coding Examples and Tips for JavaScript Code
strict mode example
Use strict mode to enforce modern JavaScript syntax and catch errors early:
‘use strict’;
Use const and let
Always declare variables with const or let, rather than var:
// Use let
let name = ‘John Doe’;
// Use const
const PI = 3.14;
Use Arrows functions
Use arrow functions instead of function for cleaner and concise code:
// Function expression
const multiply = (a, b) => a * b;
// Implicit return
const square = x => x * x;
Use Destructuring to get values from arrays
Make use of destructuring to extract values from arrays and objects into variables:
// Destructuring arrays
const colors = [‘red’, ‘green’, ‘blue’];
const [first, second, third] = colors;
// Destructuring objects
const person = {
name: ‘John Doe’,
age: 30,
job: ‘Software Engineer’
};
const { name, age, job } = person;
Use template literals
Use template literals for string concatenation and embedding expressions:
const name = ‘John Doe’;
const message = `Hello, ${name}!`;
Use forEach over for loop
Prefer forEach over for loop for simple iterations:
const numbers = [1, 2, 3, 4, 5];
numbers.forEach(number => console.log(number));
use of higher-order functions
Make use of higher-order functions like map, filter, and reduce to process arrays:
const numbers = [1, 2, 3, 4, 5];
// Use map
const double = numbers.map(number => number * 2);
// Use filter
const even = numbers.filter(number => number % 2 === 0);
// Use reduce
const sum = numbers.reduce((acc, number) => acc + number, 0);
Avoid Global Variables
Avoid using global variables and always use const or let to scope variables:
// Global variable (not recommended)
let name = ‘John Doe’;
// Scoped variable (recommended)
function sayHello() {
const name = ‘John Doe’;
console.log(`Hello, ${name}!`);
}
Avoid Naming Collisions
Use modules to organize your code and avoid naming collisions:
// math.js
export const PI = 3.14;
export const add = (a, b) => a + b;
// main.js
import { PI, add } from ‘./math.js’;
console.log(PI); // 3.14
console.log(add(1, 2)); // 3
Initialize variables with default values
Always initialize variables with default values to avoid undefined values:
// Default value
let name = ‘John Doe’;
// Default value with destructuring
const person = {
name = ‘John Doe’,
age: 30
};
const { name, age = 0 } = person;