Java番石榴 |带有示例的 Booleans.lastIndexOf() 方法

Guava 库中Booleans 类的lastIndexOf()方法用于查找给定布尔值在布尔数组中的最后一个索引。这个要搜索的布尔值和要搜索的布尔数组，都作为参数传递给这个方法。它返回一个整数值，它是指定布尔值的最后一个索引。如果未找到该值，则返回 -1。

句法：

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

参数：此方法接受两个强制参数：

• 数组：这是要在其中搜索布尔值的布尔值数组。
• target：这是要在布尔数组中搜索最后一个索引的布尔值。

返回值：此方法返回一个整数值，它是指定布尔值的最后一个索引。如果未找到该值，则返回 -1。

下面的程序说明了这种方法：

示例 1：

// Java code to show implementation of
// Guava's Booleans.lastIndexOf() 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 = { true, false, false,
                          true, true };
  
        boolean target = true;
  
        // Using Booleans.lastIndexOf() method
        // to get the index of last appearance
        // of a given element in array
        // and return -1 if element
        // is not found in the array
        int index = Booleans.lastIndexOf(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");
        }
    }
}

输出：

Target is present at index 4

示例 2：

// Java code to show implementation of
// Guava's Booleans.lastIndexOf() 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 = { true, true, true,
                          true, true };
  
        boolean target = false;
  
        // Using Booleans.lastIndexOf() method to get the
        // index of last appearance of a given element
        // in array and return -1 if element is
        // not found in the array
        int index = Booleans.lastIndexOf(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");
        }
    }
}

输出：

Target is not present in the array

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