blocks|key|812998|text|如下所示：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|812999|String[][]+arrays+=+{+array1,+array2,+array3,+array4,+array5+};|code-block|syntax|javascript|813000|或|813001|String[][]+arrays+=+new+String[][]+{+array1,+array2,+array3,+array4,+array5+};|813002|(后一种语法可以在变量声明点以外的赋值中使用，而较短的语法仅适用于声明。)|813003|entityMap^0|0|0|0|0|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]]|$1|G|3|H|5|6|7|Q|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|S|8|@]|9|@]|A|$]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

Like this:

<pre><code>String[][] arrays = { array1, array2, array3, array4, array5 };
</code></pre>

or

<pre><code>String[][] arrays = new String[][] { array1, array2, array3, array4, array5 };
</code></pre>

(The latter syntax can be used in assignments other than at the point of the variable declaration, whereas the shorter syntax only works with declarations.)

blocks|key|812934|text|试一试|type|unstyled|depth|inlineStyleRanges|entityRanges|data|812935|String[][]+arrays+=+new+String[5][];|code-block|syntax|javascript|812936|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|$]]

try

<pre><code>String[][] arrays = new String[5][];
</code></pre>

blocks|key|1027900|text|虽然有两个很好的答案告诉你如何做到这一点，但我觉得另一个答案缺失了:在大多数情况下，你根本不应该这样做。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1027901|数组很麻烦，在大多数情况下，您最好使用Collection+API。|offset|length|1027902|使用Collections，您可以添加和删除元素，并且有针对不同功能(基于索引的查找、排序、唯一性、FIFO访问、并发性等)的专用Collections。|1027903|虽然了解数组及其用法当然很重要，但在大多数情况下，使用集合可以使API更易于管理(这就是为什么像Google+Guava这样的新库几乎不使用数组)。|1027904|因此，对于您的场景，我更喜欢使用列表列表，并使用Guava创建它：|1027905|List<List<String>>+listOfLists+=+Lists.newArrayList();
listOfLists.add(Lists.newArrayList("abc","def","ghi"));
listOfLists.add(Lists.newArrayList("jkl","mno","pqr"));|code-block|syntax|javascript|1027906|entityMap|0|LINK|mutability|MUTABLE|url|http://download.oracle.com/javase/6/docs/api/java/util/Collection.html|1|http://code.google.com/p/guava-libraries/^0|0|J|E|0|0|0|1C|C|1|0|0|0^^$0|@$1|2|3|4|5|6|7|10|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|11|8|@]|9|@$D|12|E|13|1|14]]|A|$]]|$1|F|3|G|5|6|7|15|8|@]|9|@]|A|$]]|$1|H|3|I|5|6|7|16|8|@]|9|@$D|17|E|18|1|19]]|A|$]]|$1|J|3|K|5|6|7|1A|8|@]|9|@]|A|$]]|$1|L|3|M|5|N|7|1B|8|@]|9|@]|A|$O|P]]|$1|Q|3|-4|5|6|7|1C|8|@]|9|@]|A|$]]]|R|$S|$5|T|U|V|A|$W|X]]|Y|$5|T|U|V|A|$W|Z]]]]

While there are two excellent answers telling you how to do it, I feel that another answer is missing: In most cases you shouldn't do it at all.

Arrays are cumbersome, in most cases you are better off using the <a href="http://download.oracle.com/javase/6/docs/api/java/util/Collection.html" rel="noreferrer">Collection API</a>.

With Collections, you can add and remove elements and there are specialized Collections for different functionality (index-based lookup, sorting, uniqueness, FIFO-access, concurrency etc.).

While it's of course good and important to know about Arrays and their usage, in most cases using Collections makes APIs a lot more manageable (which is why new libraries like <a href="http://code.google.com/p/guava-libraries/" rel="noreferrer">Google Guava</a> hardly use Arrays at all).

So, for your scenario, I'd prefer a List of Lists, and I'd create it using Guava:

<pre><code>List&lt;List&lt;String&gt;&gt; listOfLists = Lists.newArrayList();
listOfLists.add(Lists.newArrayList("abc","def","ghi"));
listOfLists.add(Lists.newArrayList("jkl","mno","pqr"));
</code></pre>

blocks|key|813155|text|有一个我在与Sean+Patrick+Floyd的评论中提到的类:我用了一个特殊的用法，它需要WeakReference，但你可以很容易地通过任何对象来更改它。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|813156|希望有一天这能帮助到某个人:)|813157|import+java.lang.ref.WeakReference;
import+java.util.LinkedList;
import+java.util.NoSuchElementException;
import+java.util.Queue;


/**
+*
+*+@author+leBenj
+*/
public+class+Array2DWeakRefsBuffered<T>
{
++++private+final+WeakReference<T>[][]+_array;
++++private+final+Queue<T>+_buffer;

++++private+final+int+_width;

++++private+final+int+_height;

++++private+final+int+_bufferSize;

++++@SuppressWarnings(+"unchecked"+)
++++public+Array2DWeakRefsBuffered(+int+w+,+int+h+,+int+bufferSize+)
++++{
++++++++_width+=+w;
++++++++_height+=+h;
++++++++_bufferSize+=+bufferSize;
++++++++_array+=+new+WeakReference[_width][_height];
++++++++_buffer+=+new+LinkedList<T>();
++++}

++++/**
+++++*+Tests+the+existence+of+the+encapsulated+object
+++++*+/!\+This+DOES+NOT+ensure+that+the+object+will+be+available+on+next+call+!
+++++*+@param+x
+++++*+@param+y
+++++*+@return
+++++*+@throws+IndexOutOfBoundsException
+++++*/public+boolean+exists(+int+x+,+int+y+)+throws+IndexOutOfBoundsException
++++{
++++++++if(+x+>=+_width+%7C%7C+x+<+0+)
++++++++{
++++++++++++throw+new+IndexOutOfBoundsException(+"Index+out+of+bounds+(get)+:+[+x+=+"+%2B+x+%2B+"]"+);
++++++++}
++++++++if(+y+>=+_height+%7C%7C+y+<+0+)
++++++++{
++++++++++++throw+new+IndexOutOfBoundsException(+"Index+out+of+bounds+(get)+:+[+y+=+"+%2B+y+%2B+"]"+);
++++++++}
++++++++if(+_array[x][y]+!=+null+)
++++++++{
++++++++++++T+elem+=+_array[x][y].get();
++++++++++++if(+elem+!=+null+)
++++++++++++{
++++++++++++return+true;
++++++++++++}
++++++++}
++++++++return+false;
++++}

++++/**
+++++*+Gets+the+encapsulated+object
+++++*+@param+x
+++++*+@param+y
+++++*+@return
+++++*+@throws+IndexOutOfBoundsException
+++++*+@throws+NoSuchElementException
+++++*/
++++public+T+get(+int+x+,+int+y+)+throws+IndexOutOfBoundsException+,+NoSuchElementException
++++{
++++++++T+retour+=+null;
++++++++if(+x+>=+_width+%7C%7C+x+<+0+)
++++++++{
++++++++++++throw+new+IndexOutOfBoundsException(+"Index+out+of+bounds+(get)+:+[+x+=+"+%2B+x+%2B+"]"+);
++++++++}
++++++++if(+y+>=+_height+%7C%7C+y+<+0+)
++++++++{
++++++++++++throw+new+IndexOutOfBoundsException(+"Index+out+of+bounds+(get)+:+[+y+=+"+%2B+y+%2B+"]"+);
++++++++}
++++++++if(+_array[x][y]+!=+null+)
++++++++{
++++++++++++retour+=+_array[x][y].get();
++++++++++++if(+retour+==+null+)
++++++++++++{
++++++++++++throw+new+NoSuchElementException(+"Dereferenced+WeakReference+element+at+[+"+%2B+x+%2B+"+;+"+%2B+y+%2B+"]"+);
++++++++++++}
++++++++}
++++++++else
++++++++{
++++++++++++throw+new+NoSuchElementException(+"No+WeakReference+element+at+[+"+%2B+x+%2B+"+;+"+%2B+y+%2B+"]"+);
++++++++}
++++++++return+retour;
++++}

++++/**
+++++*+Add/replace+an+object
+++++*+@param+o
+++++*+@param+x
+++++*+@param+y
+++++*+@throws+IndexOutOfBoundsException
+++++*/
++++public+void+set(+T+o+,+int+x+,+int+y+)+throws+IndexOutOfBoundsException
++++{
++++++++if(+x+>=+_width+%7C%7C+x+<+0+)
++++++++{
++++++++++++throw+new+IndexOutOfBoundsException(+"Index+out+of+bounds+(set)+:+[+x+=+"+%2B+x+%2B+"]"+);
++++++++}
++++++++if(+y+>=+_height+%7C%7C+y+<+0+)
++++++++{
++++++++++++throw+new+IndexOutOfBoundsException(+"Index+out+of+bounds+(set)+:+[+y+=+"+%2B+y+%2B+"]"+);
++++++++}
++++++++_array[x][y]+=+new+WeakReference<T>(+o+);

++++++++//+store+local+"visible"+references+:+avoids+deletion,+works+in+FIFO+mode
++++++++_buffer.add(+o+);
++++++++if(_buffer.size()+>+_bufferSize)
++++++++{
++++++++++++_buffer.poll();
++++++++}
++++}

}|code-block|syntax|javascript|813158|如何使用的示例：|813159|//+a+5x5+array,+with+at+most+10+elements+"bufferized"+->+the+last+10+elements+will+not+be+taken+by+GC+process
Array2DWeakRefsBuffered<Image>+myArray+=+new+Array2DWeakRefsBuffered<Image>(5,5,10);
Image+img+=+myArray.set(anImage,0,0);
if(myArray.exists(3,3))
{
++++System.out.println("Image+at+3,3+is+still+in+memory");
}|813160|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|P|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|Q|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|R|8|@]|9|@]|A|$]]|$1|K|3|L|5|F|7|S|8|@]|9|@]|A|$G|H]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

there is the class I mentioned in the comment we had with Sean Patrick Floyd : I did it with a peculiar use which needs WeakReference, but you can change it by any object with ease.

Hoping this can help someone someday :)

<pre><code>import java.lang.ref.WeakReference;
import java.util.LinkedList;
import java.util.NoSuchElementException;
import java.util.Queue;


/**
 *
 * @author leBenj
 */
public class Array2DWeakRefsBuffered&lt;T&gt;
{
 private final WeakReference&lt;T&gt;[][] _array;
 private final Queue&lt;T&gt; _buffer;

 private final int _width;

 private final int _height;

 private final int _bufferSize;

 @SuppressWarnings( "unchecked" )
 public Array2DWeakRefsBuffered( int w , int h , int bufferSize )
 {
 _width = w;
 _height = h;
 _bufferSize = bufferSize;
 _array = new WeakReference[_width][_height];
 _buffer = new LinkedList&lt;T&gt;();
 }

 /**
 * Tests the existence of the encapsulated object
 * /!\ This DOES NOT ensure that the object will be available on next call !
 * @param x
 * @param y
 * @return
 * @throws IndexOutOfBoundsException
 */public boolean exists( int x , int y ) throws IndexOutOfBoundsException
 {
 if( x &gt;= _width || x &lt; 0 )
 {
 throw new IndexOutOfBoundsException( "Index out of bounds (get) : [ x = " + x + "]" );
 }
 if( y &gt;= _height || y &lt; 0 )
 {
 throw new IndexOutOfBoundsException( "Index out of bounds (get) : [ y = " + y + "]" );
 }
 if( _array[x][y] != null )
 {
 T elem = _array[x][y].get();
 if( elem != null )
 {
 return true;
 }
 }
 return false;
 }

 /**
 * Gets the encapsulated object
 * @param x
 * @param y
 * @return
 * @throws IndexOutOfBoundsException
 * @throws NoSuchElementException
 */
 public T get( int x , int y ) throws IndexOutOfBoundsException , NoSuchElementException
 {
 T retour = null;
 if( x &gt;= _width || x &lt; 0 )
 {
 throw new IndexOutOfBoundsException( "Index out of bounds (get) : [ x = " + x + "]" );
 }
 if( y &gt;= _height || y &lt; 0 )
 {
 throw new IndexOutOfBoundsException( "Index out of bounds (get) : [ y = " + y + "]" );
 }
 if( _array[x][y] != null )
 {
 retour = _array[x][y].get();
 if( retour == null )
 {
 throw new NoSuchElementException( "Dereferenced WeakReference element at [ " + x + " ; " + y + "]" );
 }
 }
 else
 {
 throw new NoSuchElementException( "No WeakReference element at [ " + x + " ; " + y + "]" );
 }
 return retour;
 }

 /**
 * Add/replace an object
 * @param o
 * @param x
 * @param y
 * @throws IndexOutOfBoundsException
 */
 public void set( T o , int x , int y ) throws IndexOutOfBoundsException
 {
 if( x &gt;= _width || x &lt; 0 )
 {
 throw new IndexOutOfBoundsException( "Index out of bounds (set) : [ x = " + x + "]" );
 }
 if( y &gt;= _height || y &lt; 0 )
 {
 throw new IndexOutOfBoundsException( "Index out of bounds (set) : [ y = " + y + "]" );
 }
 _array[x][y] = new WeakReference&lt;T&gt;( o );

 // store local "visible" references : avoids deletion, works in FIFO mode
 _buffer.add( o );
 if(_buffer.size() &gt; _bufferSize)
 {
 _buffer.poll();
 }
 }

}
</code></pre>

Example of how to use it :

<pre><code>// a 5x5 array, with at most 10 elements "bufferized" -&gt; the last 10 elements will not be taken by GC process
Array2DWeakRefsBuffered&lt;Image&gt; myArray = new Array2DWeakRefsBuffered&lt;Image&gt;(5,5,10);
Image img = myArray.set(anImage,0,0);
if(myArray.exists(3,3))
{
 System.out.println("Image at 3,3 is still in memory");
}
</code></pre>

Hypothetically, I have 5 string array objects:

<pre><code>String[] array1 = new String[];
String[] array2 = new String[];
String[] array3 = new String[];
String[] array4 = new String[];
String[] array5 = new String[];
</code></pre>

and I want another array object to contain those 5 string array objects. How do I do it? Can I put it in another array?

How to make an array of arrays in Java

假设我有5个字符串数组对象：String[] array1 = new String[];String[] array2 = new String[];String[] array3 = new String[];String[] array4 = new String[];String[] array5 = new String[];我希望另一个数组对象包含这5个字符串数组对象。我该怎么做呢？我

问如何在Java中创建数组的数组
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