Java Guava Longs.lastIndexOf()用法及代碼示例

Guava庫中Longs類的lastIndexOf()方法用於在長數組中查找給定long值的最後一個索引。要搜索的long值和要在其中搜索的long數組均作為參數傳遞給此方法。它返回一個整數值，該整數值是指定的long值的最後一個索引。如果找不到該值，則返回-1。

用法:

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

參數：此方法接受兩個強製性參數：

array:這是要在其中搜索long值的long值數組。
target:要在long數組中搜索最後一個索引的long值。

返回值：此方法返回一個整數值，該整數值是指定的long值的最後一個索引。如果找不到該值，則返回-1。

下麵的程序演示了此方法：

範例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"); 
        } 
    } 
}

輸出：

Target is present at index 6

範例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"); 
        } 
    } 
}

輸出：

Target is not present in the array

參考： https://google.github.io/guava/releases/21.0/api/docs/com/google/common/primitives/Longs.html#lastIndexOf-long:A-long-

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注：本文由純淨天空篩選整理自Sahil_Bansall大神的英文原創作品 Java Guava | Longs.lastIndexOf() method with Examples。非經特殊聲明，原始代碼版權歸原作者所有，本譯文未經允許或授權，請勿轉載或複製。