destructuration + reduce

const dir = films.reduce( (acc, cur) => {

  acc[cur.director] = [ ... (acc[cur.director] || [] ), cur.title ];

  return acc;

}, {}); 

Décomposition : fonction fléchée

Définition

let f = ([a, b] = [10, 10], {x: c} = {x: a - b}) => a + b + c;

Paramètres

f([2,3],{x:10});

f = ([a, b], {x: c}) => a + b + c;

// 15 = 2 + 3 + 10

Paramètres

f([2,3]);

([a, b], {x: c} = {x: a - b}) => a + b + c;

// 4 = 2 + 3 + ( 2 - 3 )

Paramètres

f(); 


f = ([a, b] = [10, 10], {x: c} = {x: a - b}) => a + b + c;

// 20 = 10 + 10 + ( 10 - 10 )

map

const liste = [
{age:10,arg:2,exp:2},
{age:1,arg:1},
{age:100,arg:3},
];

function AgeArg({arg,age}){
  return age*arg;
}

let T = liste.map(AgeArg);

console.log(T);

reduce : destructuring

const liste = [
{age:10,arg:2,exp:2},
{age:1,arg:1},
{age:100,arg:3},
];

function AgeArg(acc,{arg,age}){
  return acc+ age*arg;
}

let T = liste.reduce(AgeArg,0);

console.log(T); //321

for_of

const liste = [
{age:10,arg:2,exp:2},
{age:1,arg:1},
{age:100,arg:3},
];

for_of

classique

for (l of liste){
console.log(l.age)
}

destructuring

for ({arg,age} of liste){
console.log(arg*age)
}

exemple de décomposition

Allez dans votre console et tapez :
const doc = document.documentElement;
const { clientWidth, clientHeight } = doc;
console.log( `la largeur de la fenêtre est : ${clientWidth} ` );