內容爲該問題下的答案:[链接] 是對 [链接] 的學習筆記。 對象的兩層實現 兩層實現分別爲: Named properties: in-object properties and extra properties Numbered properties: fast elements Named properties in-object properties 使用公共 map 來描述其結構,某些情況(難以共用 map)會降級爲 Dictionary mode。 ...
In JavaScript, it is true that +[] === 0. + converts something into a number, and in this case it will come down to +"" or 0 (see specification details below).