1.效率最高(最原始)

代码如下(示例):

public class Demo {

public static boolean useLoop(String[] arr, String targetValue) {

for (String s : arr) {

if (s.equals(targetValue)) return true;

}

return false;

}

public static void main(String[] args) {

String arr[] = {“aa”, “bb”, “cc”};

String targetValue = “bb”;

System.out.println(useLoop(arr, targetValue));

}

}

运行结果:

2.List数组Contains

代码如下(示例):

import java.util.Arrays;

public class Demo {

public static boolean useList(String[] arr, String targetValue) {

return Arrays.asList(arr).contains(targetValue);

}

public static void main(String[] args) {

String arr[] = {“aa”, “bb”, “cc”};

String targetValue = “bb”;

System.out.println(useList(arr, targetValue));

}

}

运行结果:

3.Set的Contains

代码如下(示例):

import java.util.Arrays;

import java.util.HashSet;

import java.util.Set;

public class Demo {

public static boolean useSet(String[] arr, String targetValue) {

Set set = new HashSet(Arrays.asList(arr));

return set.contains(targetValue);

}

public static void main(String[] args) {

String arr[] = {“aa”, “bb”, “cc”};

String targetValue = “bb”;

System.out.println(useSet(arr, targetValue));

}

}

运行结果:

4.Arrays的binarySearch

代码如下(示例):

import java.util.Arrays;

public class Demo {

public static boolean useArraysBinarySearch(String[] arr, String targetValue) {

int a = Arrays.binarySearch(arr, targetValue);

if (a > 0) {

return true;

} else {

return false;

}

}

public static void main(String[] args) {

String arr[] = {“aa”, “bb”, “cc”};

String targetValue = “bb”;

System.out.println(useArraysBinarySearch(arr, targetValue));

}

}

运行结果: