C++ Program To Traverse an Array

Given an integer array of size N, the task is to traverse and print the elements in the array.

Examples:

Input: arr[] = {2, -1, 5, 6, 0, -3} 
Output: 2 -1 5 6 0 -3

Input: arr[] = {4, 0, -2, -9, -7, 1} 
Output: 4 0 -2 -9 -7 1 

Ways to traverse the elements of an array in C++

Let's start discussing each of these methods in detail.

1. Using for Loop

Approach:

• Start a loop from 0 to N-1, where N is the size of the array.
• Use arr[i] to access each element of the array.
• Print every element using cout << arr[i] << endl;.

#include <bits/stdc++.h>
using namespace std;

void printArray(int* arr, int n){
    int i;

    cout << "Array: ";
    for (i = 0; i < n; i++) {
        cout << arr[i] << " ";
    }
}

int main(){
    int arr[] = {2, -1, 5, 6, 0, -3};
    int n = sizeof(arr) / sizeof(arr[0]);

    printArray(arr, n);
    return 0;
}

Array: 2  -1  5  6  0  -3  

2. Using a for-each loop

for_each is a powerful STL algorithm to operate on range elements and apply custom-defined functions. It takes range starting and the last iterator objects as the first two parameters and the function object as the third one.

#include <bits/stdc++.h>
using namespace std;

void display(int x){
    cout << x << " ";
}

int main(){
    int arr[] = {2, -1, 5, 6, 0, -3};

    cout << "Traverse using for_each: ";
    for_each(arr, arr + 6, display);

    return 0;
}

Traverse using for_each: 2 -1 5 6 0 -3 

3. Using range-based Loop

The range-based loop is the readable version of the for loop. The following code shows how to implement the above code using a range-based loop.

#include <bits/stdc++.h>
using namespace std;

int main(){
    int arr[] = {2, -1, 5, 6, 0, -3};
  
    for (const auto &var : arr)  {  
      cout << var << " " ;  
    } 
    return 0;
}