整数 indexOf()函数|番石榴 |Java

Guava 的Ints.indexOf(int[] array, int target)方法返回值目标在数组中第一次出现的索引。

句法：

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

参数：此方法接受以下参数：

• 数组：一个 int 值数组，可能为空。
• 目标：一个原始的 int 值。

返回值：此方法返回 array[i] == target 的最小索引i，如果不存在这样的索引，则返回-1 。

示例 1：

// Java code to show implementation of
// Guava's Ints.indexOf() method
  
import com.google.common.primitives.Ints;
import java.util.Arrays;
  
class GFG {
  
    // Driver's code
    public static void main(String[] args)
    {
  
        // Creating an integer array
        int[] arr = { 1, 2, 3, 4, 3, 5 };
  
        int target = 3;
  
        // Using Ints.indexOf(int[] array, int target)
        // method to get the index of first appearance
        // of a given element in array and return -1
        // if element is not found in the array
        int index = Ints.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");
        }
    }
}

输出：

Target is present at index 2

示例 2：

// Java code to show implementation of
// Guava's Ints.indexOf() method
  
import com.google.common.primitives.Ints;
import java.util.Arrays;
  
class GFG {
  
    // Driver's code
    public static void main(String[] args)
    {
  
        // Creating an integer array
        int[] arr = { 3, 5, 7, 11, 13 };
  
        int target = 17;
  
        // Using Ints.indexOf(int[] array, int target) method
        // to get the index of first appearance of a
        // given element in array and return -1 if
        // element is not found in the array
        int index = Ints.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");
        }
    }
}

输出：

Target is not present in the array

参考： https://google.github.io/guava/releases/22.0/api/docs/com/google/common/primitives/Ints.html#indexOf-int:A-int-