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))

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.

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