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JS 對象和數(shù)組的創(chuàng)建使用new和不使用new有什么區(qū)別呢？

JavaScript

叮當(dāng)貓咪 2018-10-12 14:11:06

比如：var a = Array(); 和 var aa = new Array();var b = Object(); 和 var bb = new Object();

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1 回答

蝴蝶刀刀

TA貢獻(xiàn)1801條經(jīng)驗(yàn) 獲得超8個(gè)贊

根據(jù)EMACScript標(biāo)準(zhǔn)：

The Array constructor is the %Array% intrinsic object and the initial value of the Array property of the global object. When called as a constructor it creates and initializes a new exotic Array object. When Array is called as a function rather than as a constructor, it also creates and initializes a new Array object. Thus the function call Array(…) is equivalent to the object creation expression new Array(…) with the same arguments.

調(diào)用Array()和new Array()是等同的。

反對回復(fù) 2018-11-26