Array and Function - c++

Question

I am trying to make functions to call in the main function, trying to keep "main" as clean as possible.
so I made a function to get the size array from the user then the user enters the elements of the function, but I got stuck at the linear search function, so want help "Still absolute beginner"
#include <iostream>
using namespace std;
int* Array_Elements () {
static int arr [5] {}, i, size;
cout << "Enter Array size: ";
cin >> size;
cout << "Enter Array Elements: " << endl;
for (i=0; i<size; i++) {
cin >> arr[i];
}
return arr;
}
void Array_Search (int arr [], int n) {
int temp = -1;
for (int i = 0; i < 5; i++) {
if (arr [i] == n) {
cout << "Element found at position: " << i + 1 << endl;
temp = 0;
break;
}
}
if (temp == -1) {
cout << "No Element Found" << endl;
}
}
int num () {
cout << "Please enter an element to search" << endl;
int num;
cin >> num;
return num;
}
int main () {
Array_Search (Array_Elements(), num());
return 0;
}

Answer 1

... trying to keep "main" as clean as possible.
Ok, thats a good motivation. Frankly, I find your main rather confusing. You try to do 3 seperate steps in one line and probably tripped over unspecified evalutation order of the function parameters. I have to admit, I don't remember if or in what version of C++ the order of evaluation of function parameters is specified. And I suggest you to not even try to remember it. Instead write code that does seperate steps in seperate steps.
Your main could look like this:
int main() {
auto arr = Array_Elements();
int number = num();
Array_Search(arr,number);
}
Even without a definition of Array_Elements(), num() or Array_Searcher one can get a rough idea of the three steps made here.
Next, global state is not clean. Your Array_Elements () cannot reasonably be called twice:
int* first_array = Array_Element();
int* second_array = Array_Element();
Both pointers would point to the same arr. The second call to Array_Element will overwrite what the first call assigned.
static int arr [5] {} as workaround to passing arrays around is a hack. It isn't the right way to solve that problem. Sloppy speaking it isn't any cleaner than a sphagetti main.
Use std::array when you want a stack allocated array with size known at compile time and std::vector for dynamic arrays. They can be passed between functions and you need not keep track of the size seperate from the array:
std::vector<int> Array_Elements() {
std::cout << "Enter Array size: ";
unsigned size = 0;
std::cin >> size;
std::vector<int> result(size);
std::cout << "Enter Array Elements: \n";
for (auto& element : result){
std::cin >> element;
}
return result;
}
The loop is a range based for-loop. In a nutshell, it iterates all elements in result and element is a reference to the elements.
Get acustomed to standard algorithms. They aren't doing something that you could not write yourself. Though, they help to write cleaner code, because instead of having several lines of code that all deal with one thing, "find an element", we can have one function call with a meaningful name: std::find.
void Array_Search(const std::vector<int>& arr,int n){
auto it = std::find(arr.begin(),arr.end(),n);
if (it == arr.end()) {
std::cout << "No Element Found\n";
} else {
std::cout << "Element found at position: " << (it - arr.begin()) << "\n";
}
}
In case the element was not found it returns the end iterator. When it does find the element we can calculate the index from an iterator by subtracting the begin iterator.
Live Demo

Answer 2

Lets jump right in, my suggestion to keep the main as clean as possible is to use a class then instantiate its object then use the object to call class methods in the main. This is best practice.
Your code confuses the compiler, in that the function num() precedes the function Array_Elements() in terms of order of evaluation. And I believe you want it the other way around.
Here's how to fix it: Remove the function num(), and make the following changes to your code
int* Array_Elements(int size) {
int* arr, i;
cout << "Enter Array Elements: " << endl;
arr = new int[size];
for (i=0; i<size; i++) {
cin >> arr[i];
}
return arr;
}
void Array_Search (int *arr, int size) {
int temp = -1, num;
cout << "Please enter an element to search" << endl;
cin >> num;
for (int i = 0; i < size; i++) {
if (arr [i] == num) {
cout << "Element found at position: " << i + 1 << endl;
temp = 0;
delete [] arr;
break;
}
}
if (temp == -1) {
cout << "No Element Found" << endl;
}
}
int main () {
int size;
cout << "Enter Array size: ";
cin >> size;
Array_Search(Array_Elements(size),size);
return 0;
}