10 JavaScript One-Liners That Will Blow Your Mind in 2025

JavaScript is a powerful language. Most of times we are writing long and complex code to get things done. But we have to keep in mind that In fact, we can achieve a lot with just one line of JS code! 🚀

In this article, we will explore 10 mind-blowing JavaScript one-liners that will save our time and make coding fun. Let’s dive in without wasting any time!

1. Reverse a String Instantly

Want to reverse a string in JavaScript? You don’t need loops. Just use one simple line like below:

const reverseString = str => str.split('').reverse().join('');
console.log(reverseString("JavaScript")); // tpircSavaJ

This code breaks the string into an array, reverses it, and joins it back. It’s a quick way to reverse any string!

2. Check if a Number is Even or Odd

Instead of using an if-else statement, use this simple one-liner:

const isEven = num => num % 2 === 0;
console.log(isEven(10)); // true

3. Shuffle an Array (Fisher-Yates Algorithm)

Want to randomly shuffle an array? Here is an smart way to do it using one line:

const shuffleArray = arr => arr.sort(() => Math.random() - 0.5);
console.log(shuffleArray([1, 2, 3, 4, 5]));

This randomizes the order of elements in an array, useful for games, quizzes, and more!

4. Remove Duplicates from an Array

Instead of using loops, use the Set object and make your code one liner. Amazing right?

const uniqueArray = arr => [...new Set(arr)];
console.log(uniqueArray([1, 2, 2, 3, 4, 4, 5])); // [1, 2, 3, 4, 5]

The Set object automatically removes duplicates, making this the easiest way to get unique values.

5. Find the Maximum Number in an Array

Forget the for loop—use Math.max and spread operator:

const maxNumber = arr => Math.max(...arr);
console.log(maxNumber([10, 20, 5, 8])); // 20

This quickly finds the largest number in an array by spreading all values into Math.max().

6. Generate a Random Hex Color

Want a random color in one line using JavaScript?

const randomColor = () => `#${Math.floor(Math.random()*16777215).toString(16)}`;
console.log(randomColor());

This generates a six-digit hex color code, perfect for styling elements dynamically.

7. Convert a String to Title Case

Make the first letter of every word uppercase with this simple JS function:

const toTitleCase = str => str.replace(/\b\w/g, char => char.toUpperCase());
console.log(toTitleCase("hello world")); // Hello World

This replaces the first letter of each word with its uppercase version. Great for formatting dashboard titles!

8. Get the Current Timestamp

No need to struggle with Date objects—use this shortcut instead:

const timestamp = () => Date.now();
console.log(timestamp());

This returns the number of milliseconds since January 1, 1970. Useful for tracking time events.

9. Convert an Object to a Query String

Turn an object into a URL-friendly query string effortlessly like below:

const toQueryString = obj => new URLSearchParams(obj).toString();
console.log(toQueryString({ name: "John", age: 30 })); 
// name=John&age=30

This helps send object data in a URL format, which is useful for APIs and links.

10. Count Occurrences of Elements in an Array

Use reduce() to count items quickly. Easy right?

const countOccurrences = arr => arr.reduce((acc, item) => ((acc[item] = (acc[item] || 0) + 1), acc), {});
console.log(countOccurrences(["apple", "banana", "apple", "orange"]));
// { apple: 2, banana: 1, orange: 1 }

This creates an object that counts how often each element appears in the array. Great for analytics!

JavaScript One-Liners – List of Code Example:

JavaScript One-Liners	Description
reverseString(str)	Reverses a string
isEven(num)	Checks if a number is even or odd
shuffleArray(arr)	Shuffles an array randomly
uniqueArray(arr)	Removes duplicates from an array
maxNumber(arr)	Finds the maximum number in an array
randomColor()	Generates a random hex color
toTitleCase(str)	Converts a string to title case
timestamp()	Gets the current timestamp
toQueryString(obj)	Converts an object to a query string
countOccurrences(arr)	Counts occurrences of elements in an array

Why These One-Liners Are Useful

• Saves time: No need to write lengthy functions.
• More readable: Cleaner and easier to understand.
• Performance optimized: Uses JavaScript’s built-in features effectively.
• Beginner-friendly: Great for learning core JS concepts quickly.

Frequently Asked Questions (FAQ)

Conclusion

These JavaScript one-liners can make your coding life easier while keeping your code clean and efficient. Try them out in your next project and impress your friends with your JavaScript mastery! 🧙‍♂️

🔥 Which one-liner blew your mind the most? Let me know in the comments!

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