blocks|key|969228|text|使用for循环。数组中没有内置任何东西。或者切换到java.util集合类。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|969229|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|$]]

Use a for loop. There's nothing built into array. Or switch to a java.util Collection class.

blocks|key|969338|text|您可能希望考虑使用Collection实现，而不是平面数组。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|969339|Collection接口定义了一个contains(Object+o)方法，该方法返回true/false。|969340|ArrayList实现定义了一个indexOf(Object+o)，它提供了一个索引，但该方法并不适用于所有的集合实现。|969341|这两种方法都需要正确实现equals()方法，您可能需要一个正确实现的hashCode()方法，以防您使用基于散列的Collection+(例如HashSet)。|969342|entityMap^0|9|A|0|0|A|H|I|17|4|1C|5|0|0|9|G|H|0|C|8|Z|A|1M|A|20|7|0^^$0|@$1|2|3|4|5|6|7|N|8|@$9|O|A|P|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|Q|8|@$9|R|A|S|B|C]|$9|T|A|U|B|C]|$9|V|A|W|B|C]|$9|X|A|Y|B|C]]|D|@]|E|$]]|$1|H|3|I|5|6|7|Z|8|@$9|10|A|11|B|C]|$9|12|A|13|B|C]]|D|@]|E|$]]|$1|J|3|K|5|6|7|14|8|@$9|15|A|16|B|C]|$9|17|A|18|B|C]|$9|19|A|1A|B|C]|$9|1B|A|1C|B|C]]|D|@]|E|$]]|$1|L|3|-4|5|6|7|1D|8|@]|D|@]|E|$]]]|M|$]]

You might want to consider using a <code>Collection</code> implementation instead of a flat array.

The <code>Collection</code> interface defines a <code>contains(Object o)</code> method, which returns <code>true</code>/<code>false</code>.

<code>ArrayList</code> implementation defines an <code>indexOf(Object o)</code>, which gives an index, but that method is not on all collection implementations.

Both these methods require proper implementations of the <code>equals()</code> method, and you probably want a properly implemented <code>hashCode()</code> method just in case you are using a hash based <code>Collection</code> (e.g. <code>HashSet</code>).

blocks|key|1183721|text|您可以使用众多Arrays.binarySearch()方法中的一种。请记住，必须首先对数组进行排序。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1183722|entityMap|0|LINK|mutability|MUTABLE|url|http://download.oracle.com/javase/6/docs/api/java/util/Arrays.html#binarySearch%2528java.lang.Object[],%2520java.lang.Object%2529^0|7|L|7|L|0|0^^$0|@$1|2|3|4|5|6|7|N|8|@$9|O|A|P|B|C]]|D|@$9|Q|A|R|1|S]]|E|$]]|$1|F|3|-4|5|6|7|T|8|@]|D|@]|E|$]]]|G|$H|$5|I|J|K|E|$L|M]]]]

You can use one of the many <a href="http://download.oracle.com/javase/6/docs/api/java/util/Arrays.html#binarySearch%28java.lang.Object[],%20java.lang.Object%29" rel="noreferrer"><code>Arrays.binarySearch()</code></a> methods. Keep in mind that the array must be sorted first.

blocks|key|969397|text|有一个用于列表的contains方法，因此您应该能够做到：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|969398|Arrays.asList(yourArray).contains(yourObject);|code-block|syntax|javascript|969399|警告:这可能不是您(或我)所期望的，请参阅下面Tom的评论。|969400|entityMap^0|8|8|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@$9|P|A|Q|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|R|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|S|8|@]|D|@]|E|$]]|$1|M|3|-4|5|6|7|T|8|@]|D|@]|E|$]]]|N|$]]

There is a <code>contains</code> method for lists, so you should be able to do:

<pre><code>Arrays.asList(yourArray).contains(yourObject);
</code></pre>

Warning: this might not do what you (or I) expect, see Tom's comment below.

blocks|key|1183784|text|使用Java+8，您可以做到这一点：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1183785|int[]+haystack+=+{1,+2,+3};
int+needle+=+3;

boolean+found+=+Arrays.stream(haystack).anyMatch(x+->+x+==+needle);|code-block|syntax|javascript|1183786|你需要做的就是|1183787|boolean+found+=+Arrays.stream(haystack).anyMatch(x+->+needle.equals(x));|1183788|如果您使用的是对象。|1183789|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|$]]

With Java 8, you can do this:

<pre><code>int[] haystack = {1, 2, 3};
int needle = 3;

boolean found = Arrays.stream(haystack).anyMatch(x -&gt; x == needle);
</code></pre>

You'd need to do 

<pre><code>boolean found = Arrays.stream(haystack).anyMatch(x -&gt; needle.equals(x));
</code></pre>

if you're working with objects.

Does Java have a built-function to allow me to linearly search for an element in an array or do I have to just use a for loop?

Finding an element in an array in Java

Java

Java有没有内置的函数，允许我线性地搜索数组中的元素，或者我只需要使用for循环？

问在Java中查找数组中的元素
EN

社区

活动

资源

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问在Java中查找数组中的元素EN

社区

活动

资源

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问在Java中查找数组中的元素
EN