ES6 での構造化代入例の詳細な説明

let [x, y, ...z] = ['a']
//"a", undefined, []

let [x, y, z] = new Set(["a", "b", "c"])
x //"a"

[x=1, y=2, z=3, o=4] = ['a', , undefined, null]
//"a", 2, 3, null、

var {bar, foo, baz: loc} = {foo: 'aaa', baz: 'bbb'}
bar //undefined
foo //"aaa"
loc //"bbb"
baz //ReferenceError: baz is not defined

var node = {
  loc: {
    start: {
      line: 1,
      column: 5
    }
  }
}
var {loc:{start:{line}}} = node
line //1
loc //ReferenceError: loc is not defined
start //ReferenceError: start is not defined