Guava – Longs.lastIndexOf()方法与实例
The lastIndexOf() method of Guava库中的Longs类 ，用于查找长数组中给定长值的最后索引。这个要搜索的长值和要搜索的长数组，都作为参数传给这个方法。它返回一个整数，这个整数是指定长值的最后索引。如果没有找到该值，它返回-1。
语法:
public static int lastIndexOf(long[] array, long target)
参数: 这个方法接受两个强制性参数。
array: 这是一个长值数组，长值将在其中被搜索。target:它是长数组中最后一个索引要搜索的长值。返回值： 该方法返回一个整数值，即指定的长值的最后索引。如果没有找到该值，则返回-1。
下面的程序说明了这个方法。
示例1:
// Java code to show implementation of// Guava's Longs.lastIndexOf() method import com.google.common.primitives.Longs;import java.util.Arrays; class GFG { // Driver's code public static void main(String[] args) { // Creating a long array long[] arr = { 1, 2, 3, 4, 3, 5, 3, 4 }; long target = 3; // Using Longs.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 = Longs.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 6
示例2:
// Java code to show implementation of// Guava's Longs.lastIndexOf() method import com.google.common.primitives.Longs;import java.util.Arrays; class GFG { // Driver's code public static void main(String[] args) { // Creating a long array long[] arr = { 3, 5, 7, 11, 13 }; long target = 17; // Using Longs.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 = Longs.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/21.0/api/docs/com/google/common/primitives/Longs.html#lastIndexOf-long:A-long-
