在Java中，如何检测一个数组中是否包含某一个数据？

在Java中，检测一个数组是否包含某一个数据，通常有四种方法：

（1）for循环

（2）转换为List，调用Arrays.asList(arr).contains方法

（3）使用Set

（4）使用Arrays.binarySearch()方法

下面为上述四种方法的具体代码实现：

1、使用for循环

publicstaticbooleanuseLoop(String[]arr,StringtargetValue){

for(Strings:arr){

if(s.equals(targetValue))

returntrue;

}

returnfalse;

}

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2、转换为List，调用Arrays.asList(arr).contains方法

publicstaticbooleanuseList(String[]arr,StringtargetValue){

returnArrays.asList(arr).contains(targetValue);

}

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3、使用Set

publicstaticbooleanuseSet(String[]arr,StringtargetValue){

SetStringset=newHashSetString(Arrays.asList(arr));

returnset.contains(targetValue);

}

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4、使用Arrays.binarySearch()方法

特别说明：binarySearch()二分查找仅适用于有序数组，如果不是有序数组，则报异常

publicstaticbooleanuseArraysBinarySearch(String[]arr,StringtargetValue){

inta=Arrays.binarySearch(arr,targetValue);

if(a0){

returntrue;

}else{

returnfalse;

}}

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扩展资料：

Java种List列表的contains方法：

该方法是通过遍历集合中的每一个元素并用equals方法比较是否存在指定的元素。

publicbooleancontains(Objecto){

IteratorEit=iterator();

if(o==null){

while(it.hasNext())

if(it.next()==null)

returntrue;

}else{

while(it.hasNext())

if(o.equals(it.next()))

returntrue;

}

returnfalse;

}

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参考资料来源：/docs.oracle.com/javase/tutorial/java/nutsandbolts/arrays.html"target="_blank"title="只支持选中一个链接时生效">Java官网-API-Arrays

参考资料来源：/docs.oracle.com/javase/7/docs/api/java/util/List.html"target="_blank"title="只支持选中一个链接时生效">Java官网-API-InterfaceList