在Javascript中声明数组时最好的做法是什么？(What are the best practices to follow when declaring an array in Javascri

在Javascript中声明数组时最好的做法是什么？(What are the best practices to follow when declaring an array in Javascript?)

当我需要声明一个新的数组时，我使用这个符号

var arr = new Array();

但是当在线测试时，例如在jsbin上 ，一个警告告诉我“使用数组文字符号[]”。

我没有找到避免使用构造函数的原因。 在某种程度上比使用[]吗？ 还是坏习惯？

有没有一个很好的理由使用var arr = []; 而不是var arr = new Array(); ？

When I need to declare a new array I use this notation

var arr = new Array();

But when testing online, for example on jsbin, a warning signals me to "Use the array literal notation []."

I didn't find a reason to avoid using the constructor. Is in some way less efficient than using []? Or is it bad practice?

Is there a good reason to use var arr = []; instead of var arr = new Array();?

最满意答案

大多数情况下 ，人们使用var a = []因为Douglas Crockford这样说 。

他的原因包括new Array()的非直观和不一致的行为：

var a = new Array(5); // an array pre-sized to 5 elements long var b = new Array(5, 10); // an array with two elements in it

注意，没有办法使用new Array()创建一个只有一个预先指定的数组元素的数组！

使用[]实际上更有效率， 更安全 ！ 可以覆盖Array构造函数并使其做奇怪的事情，但是不能覆盖[]的行为。

就个人而言，我总是使用[]语法，并且总是使用{}语法代替new Object() 。

Mostly, people use var a = [] because Douglas Crockford says so.

His reasons include the non-intuitive and inconsistent behaviour of new Array():

var a = new Array(5); // an array pre-sized to 5 elements long var b = new Array(5, 10); // an array with two elements in it

Note that there's no way with new Array() to create an array with just one pre-specified number element in it!

Using [] is actually more efficient, and safer too! It's possible to overwrite the Array constructor and make it do odd things, but you can't overwrite the behaviour of [].

Personally, I always use the [] syntax, and similarly always use {} syntax in place of new Object().