How to use the spread operator to flatten array of objects in javascript

function flatten(arr) {
  while (arr.some((item) => Array.isArray(item))) {
    arr = [].concat(...arr)
  }
  return arr
}
let arr = [1, 2, [3, 4], [5, [6, 7]]]
console.log(flatten(arr))

Đếm có bao nhiêu items giống nhau trong một array

reduce javascript. Đếm có bao nhiêu items giống nhau trong một array

jQuery on hover

Jquery on mouse over example.

Await in a for loop

How to Await in a for loop

Rest Operator for Objects

Now we can use rest on the properties of an Object. It allows us to explicitly extract certain named variables, and assign any uncalled variables into a catchall Object.

group by property javascript use reduce