10 Mind-Blowing JavaScript One-Liners

JavaScript is a powerful and expressive language that allows you to write complex functionalities in just a single line of code. Whether you’re a beginner or a seasoned developer, these one-liners will help you write cleaner, more efficient, and impressive JavaScript. Let’s dive into some mind-blowing JavaScript tricks!

1. Reverse a String

const reverseString = str => [...str].reverse().join('');

Usage:

console.log(reverseString("hello")); // "olleh"

This one-liner uses the spread operator ([...]) to convert the string into an array, reverses it, and then joins it back into a string.

2. Check If a Number Is Even

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

Usage:

console.log(isEven(4)); // true
console.log(isEven(7)); // false

This simple one-liner checks whether a number is even using the modulo (%) operator.

3. Generate a Random Number Between Two Values

const randomBetween = (min, max) => Math.random() * (max - min) + min;

Usage:

console.log(randomBetween(5, 10)); // e.g., 7.234562

This generates a random floating-point number within a specified range.

4. Shuffle an Array

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

Usage:

console.log(shuffleArray([1, 2, 3, 4, 5]));

This one-liner randomly shuffles an array using sort() with a random comparison function.

5. Remove Duplicates from an Array

const removeDuplicates = arr => [...new Set(arr)];

Usage:

console.log(removeDuplicates([1, 2, 2, 3, 4, 4, 5])); // [1, 2, 3, 4, 5]

This utilizes Set, which automatically removes duplicate values from an array.

6. Get the Last Element of an Array

const lastElement = arr => arr[arr.length - 1];

Usage:

console.log(lastElement([10, 20, 30, 40])); // 40

Retrieves the last element by using the array length minus one.

7. Capitalize the First Letter of a String

const capitalize = str => str.charAt(0).toUpperCase() + str.slice(1);

Usage:

console.log(capitalize("hello")); // "Hello"

This one-liner takes the first letter of a string, capitalizes it, and appends the rest of the string.

8. Check if an Object is Empty

const isEmptyObject = obj => Object.keys(obj).length === 0;

Usage:

console.log(isEmptyObject({})); // true
console.log(isEmptyObject({ a: 1 })); // false

By checking the length of the keys array, we can determine if an object is empty.

9. Convert RGB to Hex

const rgbToHex = (r, g, b) => `#${((1 << 24) | (r << 16) | (g << 8) | b).toString(16).slice(1)}`;

Usage:

console.log(rgbToHex(255, 99, 71)); // "#ff6347"

This one-liner converts RGB color values into a hex code using bitwise operations.

10. Get the Current Timestamp

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

Usage:

console.log(timestamp()); // 1712345678901

This one-liner returns the current timestamp in milliseconds.

Conclusion

JavaScript one-liners can be extremely powerful and save you time when coding. Whether it’s manipulating strings, working with arrays, or performing mathematical calculations, these tricks can make your code more elegant and efficient. Try them out and start coding smarter today!

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