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 -3Input: arr[] = {4, 0, -2, -9, -7, 1}
Output: 4 0 -2 -9 -7 1
There are three ways to traverse the elements of an array in C++:
- Using for loop.
- Using for_each loop.
- using range-based for loop.
Let’s start discussing each of these methods in detail.
1. Using for Loop
Below is the approach for traversing an array using the for loop.
Approach:
A. Start a loop from 0 to N-1, where N is the size of the array.
for(i = 0; i < N; i++)
B. Access every element of the array with the help of
arr[index]
C. Print the elements.
cout << arr[i] << endl;
Below is the implementation of the above approach:
- C++
C++
// C++ program to traverse // the array#include <bits/stdc++.h>using namespace std;// Function to traverse and // print the arrayvoid printArray(int* arr, int n){ int i; cout << "Array: "; for (i = 0; i < n; i++) { cout << arr[i] << " "; }}// Driver codeint 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
Time Complexity: O(n)
Auxiliary Space: O(1)
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.
Below is the C++ program to implement the above approach:
- C++
C++
// C++ program to traverse the // array using for_each loop#include <bits/stdc++.h>#include <iostream> using namespace std;// Driver codeint main(){ int arr[] = {2, -1, 5, 6, 0, -3}; // Traverse array with for_each // using array's data type cout << "Traverse using array's data type"; for(int x : arr) cout << x << " "; cout << endl; // Traverse array with for_each // using auto keyword cout << "Traverse using auto keyword"; for(auto x : arr) cout << x << " "; return 0;} |
Traverse using array's data type2 -1 5 6 0 -3 Traverse using auto keyword2 -1 5 6 0 -3
Time Complexity: O(n)
Auxiliary Space: O(1)
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.
- C++
C++
// C++ program to traverse the // array using range-based loop#include <bits/stdc++.h>#include <iostream> using namespace std;// Driver codeint main(){ int arr[] = {2, -1, 5, 6, 0, -3}; for (const auto &var : arr) { cout << var << " " ; } return 0;} |
2 -1 5 6 0 -3
Time Complexity: O(n)
Auxiliary Space: O(1)
