Need a fix for Multiple Searched Elements (Not getting the right index)

the attached image below is the expected output and the output I'm having

Expected Output

Actual output

I am getting the wrong Index when running the program I hope someone can help

Thank you!

import java.util.Scanner;

public class Multiple Search Elements {
public static boolean verify;
public static int arrayElements (int value, int [] a)
{
    int index = 0;
    
    for ( int i=0; i<a.length; i  )
    {
        if (a[i] == value)
        {
            index = i;
            verify = true;
            
        }
    }
    return index;
}

public static void main(String[] args) {
    
    Scanner sc = new Scanner(System.in);
    System.out.print("Enter array size: ");
    
    int array_length = sc.nextInt();
    
    int [] array = new int[array_length];
    
    System.out.println("Enter "   array_length   " array elements: ");
    
    for(int i=0; i<array_length; i  )
    {
        array[i] =sc.nextInt();
    }
    
    System.out.print("Enter elements to be searched: ");
    int element = sc.nextInt();
    
    int index = arrayElements(element, array);
    
    if (verify)
    {
        System.out.println("Found in index "   element    " and index "   array);
    }
    else
    {
        System.out.print("Element not found");
    }
    
    

}

}

CodePudding user response：

Consider returning a List of all the found positions:

import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;
import java.util.stream.Collectors;

public class MultipleSearchElements {

    public static List<Integer> getElementPositions(int[] array, int target) {
        List<Integer> elementPositions = new ArrayList<>();
        for (int i = 0; i < array.length; i  ) {
            if (array[i] == target) {
                elementPositions.add(i);
            }
        }
        return elementPositions;
    }

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.print("Enter array size: ");

        int arrayLength = sc.nextInt();
        int[] array = new int[arrayLength];

        System.out.printf("Enter %d array elements: ", arrayLength);
        for (int i = 0; i < arrayLength; i  ) {
            array[i] = sc.nextInt();
        }

        System.out.printf("%nEnter element to be searched: ");
        int element = sc.nextInt();

        List<Integer> elementPositions = getElementPositions(array, element);
        if (!elementPositions.isEmpty()) {
            System.out.printf("Found in index %s%n", elementPositions.stream()
                                                                     .map(Object::toString)
                                                                     .collect(Collectors.joining(" and index ")));
        } else {
            System.out.print("Element not found");
        }
    }
}

Example Usage:

Enter array size: 7
Enter 7 array elements: 9 7 1 4 3 5 7

Enter element to be searched: 7
Found in index 1 and index 6

CodePudding user response：

You're just not printing the good thing, print index

System.out.println("Found in index "   element   " and index "   index);

Then no need of verify, the convention would be to use a specific value (if possible) here use -1

public static int arrayElements(int value, int[] a) {
    int index = -1;
    for (int i = 0; i < a.length; i  ) {
        if (a[i] == value) {
            index = i;
            break;
        }
    }
    return index;
}

With a solution to read numbers on one line

int array_length = Integer.parseInt(sc.nextLine());
int[] array = new int[array_length];
System.out.println("Enter "   array_length   " array elements: ");
String[] numbers = sc.nextLine().split("\\s ");
for (int i = 0; i < array_length; i  ) { // use array_length in case there is too much numbers given
    array[i] = Integer.parseInt(numbers[i]);
}
System.out.print("Enter elements to be searched: ");
int element = Integer.parseInt(sc.nextLine());
int index = arrayElements(element, array);
if (index != -1) {
    System.out.println("Found in index "   element   " and index "   index);
} else {
    System.out.print("Element not found");
}