Guava – Booleans.indexOf方法及示例

Guava的Booleans.indexOf(boolean[] array, boolean[] target)方法接受两个参数数组和目标。如果目标存在于数组中，该方法返回其第一次出现的起始位置。如果目标在数组中不存在，该方法返回-1。

语法：

public static int indexOf(boolean[] array,
                          boolean[] target)

参数：该方法接受两个参数。

• array： 一个用于搜索序列目标的数组。
• target： 一个要搜索的数组，作为数组的子序列。

返回值： 该方法返回。

• 如果目标存在于数组中，则为目标第一次出现的起始位置。
• 如果目标在阵列中不存在，则为-1。

异常情况: 该方法没有抛出任何异常。

下面的例子说明了上述方法的实现。

例1:

// Java code to show implementation of
// Guava's Booleans.indexOf(boolean[] array,
// boolean[] target) method
  
import com.google.common.primitives.Booleans;
import java.util.Arrays;
  
class GFG {
  
    // Driver's code
    public static void main(String[] args)
    {
  
        // Creating a boolean array
        boolean[] arr = { false, true, false,
                          false, true };
  
        boolean[] target = { false, false };
  
        // Using indexOf(boolean[] array, boolean[] target)
        // method to get the start position of the first
        // occurrence of the specified target within array,
        // or -1 if there is no such occurrence.
        int index = Booleans.indexOf(arr, target);
  
        if (index != -1) {
            System.out.println("Target is present at index "
                               + index);
        }
        else {
            System.out.println("Target is not present "
                               + "in the array");
        }
    }
}

例2 :

// Java code to show implementation of
// Guava's Booleans.indexOf(boolean[] array,
// boolean[] target) method
  
import com.google.common.primitives.Booleans;
import java.util.Arrays;
  
class GFG {
  
    // Driver's code
    public static void main(String[] args)
    {
  
        // Creating a boolean array
        boolean[] arr = { false, true, false,
                          false, true };
  
        boolean[] target = { false, false, false };
  
        // Using indexOf(boolean[] array, boolean[] target)
        // method to get the start position of the first
        // occurrence of the specified target within array,
        // or -1 if there is no such occurrence.
        int index = Booleans.indexOf(arr, target);
  
        if (index != -1) {
            System.out.println("Target is present at index "
                               + index);
        }
        else {
            System.out.println("Target is not present "
                               + "in the array");
        }
    }
}

参考资料:

https://google.github.io/guava/releases/20.0/api/docs/com/google/common/primitives/Booleans.html#indexOf-boolean:A-boolean:A-