// === Arrays

var [a, b] = [1, 2];
console.log(a, b);

var foo = function () {
  return [1, 2, 3];
};

var [a, b] = foo();
console.log(a, b);


var foo = () => {
  return [1, 2, 3];
};

var [a, , b] = foo();
console.log(a, b);


var [a, ...b] = [1, 2, 3];
console.log(a, b);


var [, , , a, b] = [1, 2, 3];
console.log(a, b);


// Swap variables
var a = 1, b = 2;
[b, a] = [a, b];
console.log(a, b);



// Advance deep arrays
var [a, [b, [c, d]]] = [1, [2, [[[3, 4], 5], 6]]];
console.log("a:", a, "b:", b, "c:", c, "d:", d);


// === Objects

var {user: x} = {user: 5};
console.log(x);


var {user: x} = {user2: 5};
console.log(x);


var {prop: x, prop2: y} = {prop: 5, prop2: 10};
console.log(x, y);

// Short-hand
var { prop, prop2} = {prop: 5, prop2: 10};
console.log(prop, prop2);

// Equal to:
var { prop: prop, prop2: prop2} = {prop: 5, prop2: 10};
console.log(prop, prop2);


// Combine objects an arrays
var {prop: x, prop2: [, y]} = {prop: 5, prop2: [10, 100]};
console.log(x, y);


// Deep objects
var {
  prop: x,
  prop2: {
    prop2: {
      nested: [ , , b]
    }
  }
} = { prop: "Hello", prop2: { prop2: { nested: ["a", "b", "c"]}}};
console.log(x, b);


// All well and good, can we do more? Yes!
// Using as method parameters
var foo = function ({prop: x}) {
  console.log(x);
};

foo({invalid: 1});
foo({prop: 1});


// Can also use with the advance example

var foo = function ({
  prop: x,
  prop2: {
    prop2: {
      nested: b
    }
  }
}) {
  console.log(x, ...b);
};
foo({ prop: "Hello", prop2: { prop2: { nested: ["a", "b", "c"]}}});



// Combine with other ES6 features.
var ajax = ({ url = "localhost", port: p = 80}, ...data) => {
  console.log("Url:", url, "Port:", p, "Rest:", data);
};

ajax({
  url: "someHost"
}, "additional", "data", "hello");


// Like _.pluck
var users = [
  { user: "Name1" },
  { user: "Name2" },
  { user: "Name2" },
  { user: "Name3" }
];

var names = users.map( ({ user }) => user );
console.log(names);


// Advanced usage with Array Comprehension and default values
var users = [
  { user: "Name1" },
  { user: "Name2", age: 2 },
  { user: "Name2" },
  { user: "Name3", age: 4 }
];

[for ({ user, age = "DEFAULT AGE" } of users) console.log(user, age)];