Iterate over characters of a string in C++

Given a string str of length N, the task is to traverse the string and print all the characters of the given string.

Examples:

Input: str = “GeeksforGeeks”
Output: G e e k s f o r G e e k s

Input: str = “Coder”
Output: C o d e r

Naive Approach: The simplest approach to solve this problem is to iterate a loop over the range [0, N – 1], where N denotes the length of the string, using variable i and print the value of str[i].

Below is the implementation of the above approach:

C++

// C++ program to implement
// the above approach

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

// Function to traverse the string and
// print the characters of the string
void TraverseString(string &str, int N)
{
    // Traverse the string
    for (int i = 0; i < N; i++) {

        // Print current character
        cout<< str[i]<< " ";
    }

}

// Driver Code
int main()
{
    string str = "GeeksforGeeks";

    // Stores length of the string
    int N = str.length();

    TraverseString(str, N);
}

Output:

G e e k s f o r G e e k s

Time Complexity: O(N)
Auxiliary Space: O(1)

Auto keyword – based Approach: The string can be traversed using auto iterator.

Below is the implementation of the above approach:

C++

// C++ program to implement
// the above approach

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

// Function to traverse the string and
// print the elements of the string
void TraverseString(string &str, int N)
{
    // Traverse the string
    for (auto &ch : str) {

        // Print current character
        cout<< ch<< " ";
    }
}
// Driver Code
int main()
{
    string str = "GeeksforGeeks";

    // Stores length of the string
    int N = str.length();

    TraverseString(str, N);
}

Output:

G e e k s f o r G e e k s

Time Complexity: O(N)
Auxiliary Space: O(1)

Iterator – based Approach: The string can be traversed using iterator.

Below is the implementation of the above approach:

C++

// C++ program to implement
// the above approach

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

// Function to traverse the string and
// print the elements of the string
void TraverseString(string &str, int N)
{

    // Stores address of
    // a character of str
    string:: iterator it;

    // Traverse the string
    for (it = str.begin(); it != str.end();
                                   it++) {
        // Print current character
        cout<< *it<< " ";
    }
}

// Driver Code
int main()
{
    string str = "GeeksforGeeks";


    // Stores length of the string
    int N = str.length();
    TraverseString(str, N);
}

Output:

G e e k s f o r G e e k s

Time Complexity: O(N)
Auxiliary Space: O(1)