Check out example codes for "advance for loop in c++". It will help you in understanding the concepts better.

Code Example 1

// Illustration of range-for loop 
// using CPP code 
#include <iostream> 
#include <vector> 
#include <map> 
  
//Driver 
int main()  
{ 
    // Iterating over whole array 
    std::vector<int> v = {0, 1, 2, 3, 4, 5}; 
    for (auto i : v) 
        std::cout << i << ' '; 
      
    std::cout << '\n'; 
      
    // the initializer may be a braced-init-list 
    for (int n : {0, 1, 2, 3, 4, 5}) 
        std::cout << n << ' '; 
      
    std::cout << '\n'; 
   
    // Iterating over array 
    int a[] = {0, 1, 2, 3, 4, 5};      
    for (int n : a) 
        std::cout << n << ' '; 
      
    std::cout << '\n'; 
      
    // Just running a loop for every array 
    // element 
    for (int n : a)   
        std::cout << "In loop" << ' '; 
      
    std::cout << '\n'; 
      
    // Printing string characters 
    std::string str = "Geeks"; 
    for (char c : str)  
        std::cout << c << ' '; 
          
    std::cout << '\n'; 
  
    // Printing keys and values of a map 
    std::map <int, int> MAP({{1, 1}, {2, 2}, {3, 3}}); 
    for (auto i : MAP) 
        std::cout << '{' << i.first << ", " 
                  << i.second << "}\n"; 
}

Code Example 2

0 1 2 3 4 5 
0 1 2 3 4 5 
0 1 2 3 4 5 
In loop In loop In loop In loop In loop In loop 
G e e k s 
{1, 1}
{2, 2}
{3, 3}

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