myJS-CheatSheet

reference: https://www.toptal.com/javascript/interview-questions

1. var fruits = ["Banana", "Orange", "Apple", "Mango"]; var a = fruits.indexOf("Apple")

2. 'aeiou'.includes('i')

3. var objclone = Object.assign({},obj);

4. var myArray = ['a', 'b', 'c', 'd']; myArray.push('end'); myArray.unshift('start'); console.log(myArray); // ["start", "a", "b", "c", "d", "end"] With ES6, one can use the spread operator:

   myArray = ['start', ...myArray]; myArray = [...myArray, 'end'];

5. Array.from(Array(b).keys(),(e)=> e+1); // create array from 1 t0 b

6. Arr.reduce((a,b)=>(a+b),0); // get the sum of array

7. number.toString(10) // change number to string

8. s.substring(0,s.length-2) s.slice() // slice string

9. '#'.repeat(i+1).padStart(n)

10. string repeat padstart slice substring split

11. array: forEach reverse reduce Array.from() indexOf keys

12. set: has size

13. map: size forEach has set get keys values