Develop a function in c++ that can be called to sequentially search an array of integers for a given element value and return the index of the element if it is found in the array.​

#include <iostream>

#include <ctype.h>

#include <vector>

#include <algorithm>

using namespace std;

int findValue1(int* pArray, int nrElements, int value) {

   for (int i = 0; i < nrElements; i++) {

       if (pArray[i] == value) {

           return i;

       }

   }

   return -1;

}

void test1(int* pArray, int nrElements, int value) {

   int index = findValue1(pArray, nrElements, value);

   if (index >= 0) {

       cout << value << " is found at index " << index << endl;

   }

   else {

       cout << value << " is not in the array" << endl;

   }

}

int findValue2(std::vector<int> vec, int value) {

   std::vector<int>::iterator it = std::find(vec.begin(), vec.end(), value);

   if (it != vec.end()) {

       return it - vec.begin();

   }

   return -1;

}

void test2(std::vector<int> vec, int value) {

   int index = findValue2(vec, value);

   if (index >= 0) {

       cout << value << " is found at index " << index << endl;

   }

   else {

       cout << value << " is not in the array" << endl;

   }

}

int main() {

   int arr[] = { 4, 8, 15, 16, 23, 42 };

   int nrElements = sizeof(arr) / sizeof(int);

   test1(arr, nrElements, 0);

   test1(arr, nrElements, 15);

   test1(arr, nrElements, 42);

   test1(arr, nrElements, 7);

   std::vector<int> vec(std::begin(arr), std::end(arr));

   test2(vec, 0);

   test2(vec, 15);

   test2(vec, 42);

   test2(vec, 7);

}

Explanation:

Here are two solutions. One old-school array approach, and a standard library (STL) alternative.