blocks|key|1326312|text|它意味着一个数组。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1326313|var+openTollDebug+=+[];|code-block|syntax|javascript|1326314|声明openTollDebug变量并将其初始化为空数组。要将元素放入数组中，可以执行以下操作：|offset|length|style|CODE|1326315|var+stringArray+=+['element1',+'element2',+'element3'];
alert(stringArray[1]);+//+displays+'element2'
var+numberArray+=+[1,+2,+3,+4];
alert(numberArray[2]);+//+displays+3
var+objectArray+=+[{+name:+'john'+},+{+name:+'peter'+},+{+name:+'tom'+}];
alert(objectArray[1].name);+//+displays+'peter'|1326316|entityMap^0|0|0|2|D|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|S|8|@$I|T|J|U|K|L]]|9|@]|A|$]]|$1|M|3|N|5|D|7|V|8|@]|9|@]|A|$E|F]]|$1|O|3|-4|5|6|7|W|8|@]|9|@]|A|$]]]|P|$]]

It means an array.

<pre><code>var openTollDebug = [];
</code></pre>

declares the <code>openTollDebug</code> variable and initializes it to an empty array. To put elements into the array you could do the following:

<pre><code>var stringArray = ['element1', 'element2', 'element3'];
alert(stringArray[1]); // displays 'element2'
var numberArray = [1, 2, 3, 4];
alert(numberArray[2]); // displays 3
var objectArray = [{ name: 'john' }, { name: 'peter' }, { name: 'tom' }];
alert(objectArray[1].name); // displays 'peter'
</code></pre>

blocks|key|1326386|text|它是一个数组文字。它与声明数组不完全相同--可以在JavaScript中重写new+Array()对象，但不能重写数组文字。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1326387|//+let's+overwrite+the+Array+object
Array+=+function(id)+{
+this.id+=+id;
}

var+a+=+new+Array(1);
var+b+=+[];

console.log(a.hasOwnProperty("id"));+//+true
console.log(b.hasOwnProperty("id"));+//+false

console.log(a.push);+//+false,+push+doesn't+exist+on+a
console.log(b.push);+//+true,++but+it+does+on+b

b.push(2);
console.log(b);+//+outputs+[2]|code-block|syntax|javascript|1326388|entityMap^0|12|B|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|P|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|Q|8|@]|D|@]|E|$]]]|L|$]]

it is an array literal. It is not quite the same as declaring <code>new Array()</code> - the Array object can be overwritten in JavaScript, but the array literal can't. Here's an example to demonstrate

<pre><code>// let's overwrite the Array object
Array = function(id) {
 this.id = id;
}

var a = new Array(1);
var b = [];

console.log(a.hasOwnProperty("id")); // true
console.log(b.hasOwnProperty("id")); // false

console.log(a.push); // false, push doesn't exist on a
console.log(b.push); // true, but it does on b

b.push(2);
console.log(b); // outputs [2]
</code></pre>

blocks|key|1111260|text|它是一个空数组，等于|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1111261|var+openTollDebug+=+new+Array();|code-block|syntax|javascript|1111262|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

It's an empty array, and is equal to

<pre><code>var openTollDebug = new Array();
</code></pre>

blocks|key|1111342|text|它是空数组的简写。与new+Array()相同。此外，{}是一个空对象。对象就像Js中的哈希表，所以你可以把它当做字典使用。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1111343|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

It is shorthand for empty array. Same as new Array(). 
Also {} is an empty object. Objects are like hashtables in Js so you can use it as a dictionary.

blocks|key|1326543|text|它会创建一个空数组。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1326544|这是拥有一个非空对象的好方法。|1326545|在JavaScript中，向对象添加函数和属性非常容易。例如：|1326546|openTollDebug.title+=+'hello+world';
openTollDebug.show+=+function(){alert('Debug');};|code-block|syntax|javascript|1326547|作为数组，您可以添加以下项：|1326548|openTollDebug.push('added+item');
openTollDebug[3]+=+'just+add+anywhere';|1326549|entityMap^0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|R|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|S|8|@]|9|@]|A|$]]|$1|F|3|G|5|H|7|T|8|@]|9|@]|A|$I|J]]|$1|K|3|L|5|6|7|U|8|@]|9|@]|A|$]]|$1|M|3|N|5|H|7|V|8|@]|9|@]|A|$I|J]]|$1|O|3|-4|5|6|7|W|8|@]|9|@]|A|$]]]|P|$]]

It creates an empty array. 
This is a good way to have a non-null object. 
In JavaScript, it is then very easy to add functions and properties to that object. For example:

<pre><code>openTollDebug.title = 'hello world';
openTollDebug.show = function(){alert('Debug');};
</code></pre>

As an array, you can add items:

<pre><code>openTollDebug.push('added item');
openTollDebug[3] = 'just add anywhere';
</code></pre>

blocks|key|1326608|text|许多语言都有文字的构造。[]是一个数组文字。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1326609|var+openTollDebug+=+[];|code-block|syntax|javascript|1326610|等同于|1326611|var+openTollDebug+=+new+Array();|1326612|只需知道，出于性能原因，首选使用[]。|1326613|还有其他的文字，如对象文字|1326614|var+MyObject+=+{
++++++++++++++name:'default',
++++++++++++++age:22,
++++++++++++++hobbies:["golf","video+games","otherstuff"]
}|1326615|请注意包含数据的数组文字。[]创建一个空数组。|1326616|entityMap^0|0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|V|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|W|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|X|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|Y|8|@]|9|@]|A|$]]|$1|M|3|N|5|6|7|Z|8|@]|9|@]|A|$]]|$1|O|3|P|5|D|7|10|8|@]|9|@]|A|$E|F]]|$1|Q|3|R|5|6|7|11|8|@]|9|@]|A|$]]|$1|S|3|-4|5|6|7|12|8|@]|9|@]|A|$]]]|T|$]]

Many languages have constructs for literals. The [] is an Array literal. 

<pre><code>var openTollDebug = [];
</code></pre>

is the same as

<pre><code>var openTollDebug = new Array();
</code></pre>

Just know that using [] preferred for performance reasons. 

There are other literals like Object literals

<pre><code>var MyObject = {
 name:'default',
 age:22,
 hobbies:["golf","video games","otherstuff"]
}
</code></pre>

Notice the array literal with data. The [] creates an empty array.

blocks|key|1111462|text|var+b+=+[]+//it+is+an+array+literal.|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1111463|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>var b = [] //it is an array literal.
</code></pre>

blocks|key|1326690|text|由于性能原因，请尝试使用文字。你不写|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1326691|var+obj+=+new+Object({name:+'John'})|code-block|syntax|javascript|1326692|你只要写下|1326693|var+obj+=+{name:+'John'}|1326694|你也不写|1326695|button.onclick+=+new+Function("alert('Clicked!')");+|1326696|你写|1326697|button.onclick+=+function+()+{+alert('Clicked')+}|1326698|这是一篇很好的博客文章的a+link|offset|length|1326699|entityMap|0|LINK|mutability|MUTABLE|url|http://yuiblog.com/blog/2006/11/13/javascript-we-hardly-new-ya/^0|0|0|0|0|0|0|0|0|C|6|0|0^^$0|@$1|2|3|4|5|6|7|14|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|15|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|16|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|17|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|18|8|@]|9|@]|A|$]]|$1|M|3|N|5|D|7|19|8|@]|9|@]|A|$E|F]]|$1|O|3|P|5|6|7|1A|8|@]|9|@]|A|$]]|$1|Q|3|R|5|D|7|1B|8|@]|9|@]|A|$E|F]]|$1|S|3|T|5|6|7|1C|8|@]|9|@$U|1D|V|1E|1|1F]]|A|$]]|$1|W|3|-4|5|6|7|1G|8|@]|9|@]|A|$]]]|X|$Y|$5|Z|10|11|A|$12|13]]]]

Try to use literals due to performance. You dont write

<pre><code>var obj = new Object({name: 'John'})
</code></pre>

You just write 

<pre><code>var obj = {name: 'John'}
</code></pre>

You also dont write

<pre><code>button.onclick = new Function("alert('Clicked!')"); 
</code></pre>

You write

<pre><code>button.onclick = function () { alert('Clicked') }
</code></pre>

And here's <a href="http://yuiblog.com/blog/2006/11/13/javascript-we-hardly-new-ya/" rel="nofollow">a link</a> to a nice blog post about it

In the following javascript code there is <code>[]</code> being assigned as the value of a variable, what does it mean?

<pre><code>var openTollDebug = [];
</code></pre>

What does [] mean in JavaScript?

在下面的javascript代码中，[]被指定为变量的值，这是什么意思？var openTollDebug = [];

问[]在JavaScript中是什么意思？
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