名稱/值配對
A name/value pair: A name which maps to a unique value.
The name may be defined more than once, but only can have one value in any given context. That value may be more name/value pairs.
一段在執行的程式碼同名稱只會有一個,而一個名稱只能被一個值定義。
物件
A collection of name value pairs.
物件,就是名稱/值配對的組合。