package zaLearnpackage;
import org.apache.commons.lang3.ArrayUtils;
import java.util.Arrays;
import java.util.HashSet;
import java.util.Set;//检查数组是否包含某个值的方法
public classTestArray {//使用List
public staticboolean useList(String[] arr,String targetValue){returnArrays.asList(arr).contains(targetValue);
}//使用Set
public staticboolean useSet(String[] arr,String targetValue){
Set set=new HashSet(Arrays.asList(arr));return set.contains(targetValue);
}//使用循环判断 (效率最高)
public staticboolean useLoop(String[] arr,String targetValue){for(String s:arr){if(s.equals(targetValue))return true;
}return false;
}//查找有序数组中是否包含某个值的用法
public staticboolean useArraysBinarySearch(String[] arr,String targetValue){int a=Arrays.binarySearch(arr, targetValue);if(a>0)return true;else
return false;
}//使用ArrayUtils
public staticboolean useArrayUtils(String[] arr,String targetValue){returnArrayUtils.contains(arr,targetValue);
}public static voidmain(String[] args) {
String[] arr=new String[]{"CD","BC","EF","DE","AB","JK"};//use list
long startTime=System.nanoTime();for(int i=0;i<100000;i++){
useList(arr,"A");
}long endTime=System.nanoTime();long duration=endTime-startTime;
System.out.println("useList:"+duration/1000000);//use set
long startTime2=System.nanoTime();for(int i=0;i<100000;i++){
useSet(arr,"A");
}long endTime2=System.nanoTime();long duration2=endTime2-startTime2;
System.out.println("useSet:"+duration/1000000);//use loop
long startTime3=System.nanoTime();for(int i=0;i<100000;i++){
useLoop(arr,"A");
}long endTime3=System.nanoTime();long duration3=endTime3-startTime3;
System.out.println("useLoop:"+duration/1000000);//use Arrays.binarySearch()
long startTime4=System.nanoTime();for(int i=0;i<100000;i++){
useArraysBinarySearch(arr,"A");
}long endTime4=System.nanoTime();long duration4=endTime4-startTime4;
System.out.println("useArraysBinarySearch:"+duration/1000000);
}
}