1. Deep clone object
This one-Liner will make a Deep clone of a javascript object:
const originalObject = { "studentId": 26334, "studentName":"John Doe", "totalMarks": 348.50 }; const clonedObject = structuredClone(originalObject); console.log("Student details: ", clonedObject); // Output: { studentId: 26334, studentName: "John Doe", totalMarks: 348.5 } 2. Truncate a String To a Specific Length
This is One-Liner is to truncate a string and add "..." to an end on a specific given length
const originalString = "The quick brown fox jumps over the lazy dog"; const truncate = (str, len) => str?.length > len ? str.slice(0, len) + "..." : str; console.log("Truncated string: ", truncate(originalString, 9)); // Output: The quick... 3. Remove duplicate elements in array
This one-Liner will return a new array without duplicate elements from original array
const originalArray = [9,'a',8,'a','b',9,5,3,9,3.5,'b']; const removeDuplicates = arr => [...new Set(arr)] console.log("Array without duplicates: ", removeDuplicates(originalArray)); // Output: [ 9, "a", 8, "b", 5, 3, 3.5 ] 3. Swap numbers
This one liner swaps 2 numbers:
let a=6, b=9; [a,b] = [b,a] console.log(`Swapped Values - a: ${a} b: ${b}`); // Output: Swapped Values - a: 9 b: 6 4. Flatten a nested array
This one liner helps you to flatten a nested array
const flattenArray = (arr) => [].concat(...arr); console.log("Flattened: ", flattenArray([1, [2, 5, 6], 7,6, [2,3]]) // Output: Flattened: [ 1, 2, 5, 6, 7, 6, 2, 3 ] 5. Scroll To Top
This one liner instantly navigates you to the top of the page:
window.scrollTo(0, 0) 6. Find the Last Occurrence in an Array:
This one liner returns last occurrence of element in an array:
const lastIndexOf = (arr, item) => arr.lastIndexOf(item); console.log("Last index of 7 is: ", lastIndexOf([7, 5, 6 , 7 , 3 , 4], 7)) // Output: Last index of 7 is: 3 7. Make Your Code Wait for a Specific Time
Sometimes we want to make our code wait out for a seconds,
const waitForIt = ms => new Promise(resolve => setTimeout(resolve, ms)); (async () => { console.log("Before waiting"); await waitForIt(5000); console.log("After waiting for 5 seconds"); })(); /* Output: Before waiting Promise { <state>: "pending" } After waiting for 5 seconds */ 8. Extract a Property from an Array of Objects
Need to grab a specific property from an array of objects? Cherry-pick it!
const getValuesOfAKey = (arr, key) => arr.map(obj => obj[key]); console.log("Values of a: ", getValuesOfAKey([{a: 1}, {a: 2}], 'a')); // Output: Values of a: Array [ 1, 2 ] 9. Generate a Random Hexadecimal Color Code:
Get a random hex color code!
const randomColor = "#" + (~~(Math.random() * 8**8)).toString(16).padStart(6,0); console.log("Generated code: ", randomColor); // Output: Generated code: #0cf199 10. Remove falsy values from array
const removeFalsy = (arr) => arr.filter(Boolean); // or as suggested by Jon Randy const removeFalsy = arr => arr.filter(x=>x) console.log("Without falsy:", removeFalsy([true, false, undefined, NaN, null, false, true])) // Output: Without falsy: [ true, true ] 
Top comments (2)
The last one can be shorter:
Updated. Thanks!