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]

Convert Array-like to True Array

promise in javascript

Spread Operator for Objects

Using the spread operator during an Object declaration will assign the properties of the referenced Object to the new Object.

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.

Ajax, call jQuery POST to node.js expressjs