One-Liner JavaScript Snippets

A collection of useful one-liner JavaScript snippets for your next project.

1. Capitalize Text

const capitalize = (str) => `${str.charAt(0).toUpperCase()}${str.slice(1)}`;

Description: The capitalize function takes a string as input and returns a new string with the first character converted to uppercase while leaving the rest of the string unchanged.

2. Calculate Percent

const calculatePercent = (value, total) => Math.round((value / total) * 100);

Description: Calculates the percentage of value relative to total, rounded to the nearest integer. It includes error handling for non-numeric inputs and checks for a zero total to prevent division by zero.

3. Get a Random Element

const getRandomItem = (items) => items[Math.floor(Math.random() * items.length)];

Description: Returns a random element from an array.

4. Check if a String is a Palindrome

const isPalindrome = (str) => str === str.split("").reverse().join("");

Description: Checks if a given string is a palindrome (reads the same backward as forward).

5. Reverse a String

const reversedString = (str) => str.split("").reverse().join("");

Description: Reverses the characters in a string.

6. Shuffle an Array

const shuffleArray = (arr) => arr.sort(() => 0.5 - Math.random());

Description: Randomly shuffles the elements of an array.

7. Check if a Number is Even

const isEven = (num) => num % 2 === 0;

Description: Returns true if the number is even, false otherwise.

8. Get the Length of an Object

const objectLength = (obj) => Object.keys(obj).length;

Description: Returns the number of properties in an object.

9. Deep Clone an Object (Simple Implementation)

const deepClone = (obj) => JSON.parse(JSON.stringify(obj));

Description: Creates a deep clone of an object. This method is simple but may not work for objects with functions or undefined values.

10. Convert a Number to a Boolean (Truthy or Falsy)

const isTruthy = (num) => !!num;

Description: Converts a number to its boolean equivalent (truthy or falsy).