30 Essential One‑Line JavaScript Tricks to Boost Your Coding Efficiency

JavaScript is known for its flexibility and expressive power; here are several concise one‑line solutions that achieve complex functionality.

1. Array Operation Mastery

Array deduplication

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

Array flattening

const flatten = arr => arr.flat(Infinity);
// Example
const nested = [1, [2, 3], [4, [5, 6]]];
console.log(flatten(nested)); // [1, 2, 3, 4, 5, 6]

Generate numeric range

const range = (start, end) => [...Array(end - start + 1)].map((_, i) => start + i);
// Example
console.log(range(1,5)); // [1, 2, 3, 4, 5]

2. String Handling Tricks

Generate random string

const randomString = length => Math.random().toString(36).substring(2, length + 2);
// Example
console.log(randomString(10)); // "a1b2c3d4e5"

String reversal

const reverse = str => str.split('').reverse().join('');
// Example
console.log(reverse('hello')); // "olleh"

Palindrome check

const isPalindrome = str => str === str.split('').reverse().join('');
// Example
console.log(isPalindrome('radar')); // true
console.log(isPalindrome('hello')); // false

3. Object Mastery

Deep clone object

const deepClone = obj => JSON.parse(JSON.stringify(obj));
// Example
const original = { a: 1, b: { c: 2 } };
const clone = deepClone(original);

Merge multiple objects

Extract object fields

4. Functional Programming Techniques

Function composition

Function currying

5. Date and Time Handling

Format date

Calculate time difference

6. DOM Manipulation Tricks

Collect all form data

Smooth scroll to top

7. Useful Utility Functions

Debounce function

Throttle function

const throttle = (fn, delay) => {
    let last = 0;
    return (...args) => {
        const now = Date.now();
        if (now - last >= delay) {
            fn(...args);
            last = now;
        }
    };
};
// Example
const throttledScroll = throttle(handleScroll, 100);

Feel free to add more.