text: /* example 1.1:
  */
  function add ([x, y]) {
    return x + y
  }
  
  const sum = add([1, 2])
  console.log('add([1, 2]):', sum)
  
  
  /* example 1.2:
  */ 
  let value = [[1, 2], [3, 4]].map(([a, b]) => a + b)
  console.log(value)
  
  /* example 1.3
    set default value for parameter of a function
    parameter of function move is an object.
  */
  
  function move({x = 0, y = 10} = {}) {
    console.log('move: [x, y]:', `[${x}, ${y}]`)
    return [x, y]
  }
  
  move()
  move({
    x:22, 
    y: 33
  })
  
  /* example 4:
    an example different to example 3
  */
  
  function move1({x, y} = {x: 10, y: 10}) {
    console.log('move1: [x, y]:', `[${x}, ${y}]`)
    return [x, y]
  }
  
  move1()
  move1(22, 33)
  