Làm phẳng mảng dùng phương pháp đệ quy

let result = []
let flatten = function (arr) {
  for (let i = 0; i < arr.length; i++) {
    let item = arr[i]
    if (Array.isArray(arr[i])) {
      flatten(item)
    } else {
      result.push(item)
    }
  }
  return result
}
let arr = [1, 2, [3, 4], [5, [6, 7]]]
console.log(flatten(arr));// [1,2,3,4,5,6,7]

group by property javascript use reduce

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Làm phẳng mảng dùng phương pháp đệ quy

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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