blocks|key|905015|text|是时候熟悉ArrayList应用编程接口了，还有更多内容：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|905016|ArrayList+at+Java+6+API+Documentation|905017|对于您直接提出的问题：|905018|mainList.get(3);|905019|entityMap|0|LINK|mutability|MUTABLE|url|http://download.oracle.com/javase/6/docs/api/java/util/ArrayList.html?is-external=true^0|5|9|0|0|9|0|11|0|0|0|0|G|0^^$0|@$1|2|3|4|5|6|7|T|8|@$9|U|A|V|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|W|8|@$9|X|A|Y|B|C]]|D|@$9|Z|A|10|1|11]]|E|$]]|$1|H|3|I|5|6|7|12|8|@]|D|@]|E|$]]|$1|J|3|K|5|6|7|13|8|@$9|14|A|15|B|C]]|D|@]|E|$]]|$1|L|3|-4|5|6|7|16|8|@]|D|@]|E|$]]]|M|$N|$5|O|P|Q|E|$R|S]]]]

Time to familiarize yourself with the <code>ArrayList</code> API and more:

<a href="http://download.oracle.com/javase/6/docs/api/java/util/ArrayList.html?is-external=true" rel="noreferrer"><code>ArrayList</code> at Java 6 API Documentation</a> 

For your immediate question:

<code>mainList.get(3);</code>

blocks|key|905031|text|mainList.get(list_index)|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|905032|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>mainList.get(list_index)
</code></pre>

blocks|key|1119793|text|mainList.get(3);|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1119794|对于以后的参考，您应该参考Java+API来解决这些类型的问题：|unstyled|1119795|http://download.oracle.com/javase/1.4.2/docs/api/java/util/ArrayList.html|offset|length|1119796|这是一个有用的东西！|1119797|entityMap|0|LINK|mutability|MUTABLE|url^0|0|0|0|21|0|0|0^^$0|@$1|2|3|4|5|6|7|T|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|U|8|@]|9|@]|A|$]]|$1|G|3|H|5|F|7|V|8|@]|9|@$I|W|J|X|1|Y]]|A|$]]|$1|K|3|L|5|F|7|Z|8|@]|9|@]|A|$]]|$1|M|3|-4|5|F|7|10|8|@]|9|@]|A|$]]]|N|$O|$5|P|Q|R|A|$S|H]]]]

<pre><code>mainList.get(3);
</code></pre>

For future reference, you should refer to the Java API for these types of questions:

<a href="http://download.oracle.com/javase/1.4.2/docs/api/java/util/ArrayList.html" rel="noreferrer">http://download.oracle.com/javase/1.4.2/docs/api/java/util/ArrayList.html</a>

It's a useful thing!

blocks|key|905093|text|您可以直接从ArrayList+API文档中获得答案。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|905094|请始终参考API文档。这很有帮助|905095|您的呼叫将如下所示：|905096|mainList.get(3);|code-block|syntax|javascript|905097|下面是使用基础知识理解ArrayList的简单教程:)：|905098|http://www.javadeveloper.co.in/java/java-arraylist-tutorial.html|905099|entityMap|0|LINK|mutability|MUTABLE|url|http://download.oracle.com/javase/6/docs/api/java/util/ArrayList.html#get%2528int%2529|1^0|G|3|0|0|0|0|0|0|0|1S|1|0^^$0|@$1|2|3|4|5|6|7|Z|8|@]|9|@$A|10|B|11|1|12]]|C|$]]|$1|D|3|E|5|6|7|13|8|@]|9|@]|C|$]]|$1|F|3|G|5|6|7|14|8|@]|9|@]|C|$]]|$1|H|3|I|5|J|7|15|8|@]|9|@]|C|$K|L]]|$1|M|3|N|5|6|7|16|8|@]|9|@]|C|$]]|$1|O|3|P|5|6|7|17|8|@]|9|@$A|18|B|19|1|1A]]|C|$]]|$1|Q|3|-4|5|6|7|1B|8|@]|9|@]|C|$]]]|R|$S|$5|T|U|V|C|$W|X]]|Y|$5|T|U|V|C|$W|P]]]]

You can simply get your answer from ArrayList <a href="http://download.oracle.com/javase/6/docs/api/java/util/ArrayList.html#get%28int%29" rel="nofollow noreferrer">API</a> doc. 

Please always refer API documentation .. it helps 

Your call will looklike following :

<pre><code>mainList.get(3);
</code></pre>

Here is simple tutorial for understanding ArrayList with Basics :) :

<a href="http://www.javadeveloper.co.in/java/java-arraylist-tutorial.html" rel="nofollow noreferrer">http://www.javadeveloper.co.in/java/java-arraylist-tutorial.html</a>

blocks|key|1119887|text|正如许多人已经告诉你的那样：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1119888|mainList.get(3);|code-block|syntax|javascript|1119889|请务必检查ArrayList+Javadoc。|offset|length|1119890|另外，要注意数组索引:在Java语言中，第一个元素在索引0处。因此，如果您尝试获取第三个元素，那么您的解决方案将是mainList.get(2);|style|CODE|1119891|entityMap|0|LINK|mutability|MUTABLE|url|http://docs.oracle.com/javase/7/docs/api/java/util/ArrayList.html^0|0|0|5|H|0|0|S|1|1L|G|0^^$0|@$1|2|3|4|5|6|7|W|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|X|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Y|8|@]|9|@$I|Z|J|10|1|11]]|A|$]]|$1|K|3|L|5|6|7|12|8|@$I|13|J|14|M|N]|$I|15|J|16|M|N]]|9|@]|A|$]]|$1|O|3|-4|5|6|7|17|8|@]|9|@]|A|$]]]|P|$Q|$5|R|S|T|A|$U|V]]]]

As many have already told you:

<pre><code>mainList.get(3);
</code></pre>

Be sure to check the <a href="http://docs.oracle.com/javase/7/docs/api/java/util/ArrayList.html" rel="noreferrer">ArrayList Javadoc</a>.

Also, be careful with the arrays indices: in Java, the first element is at index <code>0</code>. So if you are trying to get the third element, your solution would be <code>mainList.get(2);</code>

blocks|key|1119916|text|我们使用mainList.get(+index+)打印值，其中index以'0‘开头。例如:+mainList.get(2)打印列表中的第三个元素。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1119917|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|$]]

We print the value using mainList.get(index) where index starts with '0'.
For Example: mainList.get(2) prints the 3rd element in the list.

blocks|key|905300|text|尝试：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|905301|ArrayListname.get(index);|code-block|syntax|javascript|905302|其中index是索引中的位置，ArrayListname是数组列表的名称，在本例中是mainList。|offset|length|style|CODE|905303|entityMap^0|0|0|2|5|F|D|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Q|8|@$I|R|J|S|K|L]|$I|T|J|U|K|L]]|9|@]|A|$]]|$1|M|3|-4|5|6|7|V|8|@]|9|@]|A|$]]]|N|$]]

Try:

<pre><code>ArrayListname.get(index);
</code></pre>

Where <code>index</code> is the position in the index and <code>ArrayListname</code> is the name of the Arraylist as in your case is mainList.

<pre><code>public static ArrayList mainList = someList;
</code></pre>

How can I get a specific item from this <code>ArrayList</code>? <code>mainList[3]</code>?

Get specific ArrayList item

Java

public static ArrayList mainList = someList;如何从此ArrayList获取特定项目？mainList[3]

问获取特定的ArrayList项目
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