Lesson 5: Standard Library Containers and Algorithms

Activity 19: Storing User Accounts

1. First, we include the header files for the array class and input/output operations with the required namespace:

   #include <array>

2. An array of ten elements of type int is declared:

   array<int,10> balances;

3. Initially, the values of the elements are undefined since it is an array of the fundamental data type int. The array is initialized using a for loop, where each element is initialized with its index. The operator size() is used to evaluate the size of the array and the subscript operator [ ] is used to access every position of the array:

   for (int i=0; i < balances.size(); ++i) 
   {
     balances[i] = 0;
   }

4. We now want to update the value for the first and last user. We can use front() and back() to access the accounts of these users:

   balances.front() += 100;
   balances.back() += 100;

   We would like to store the account balance of an arbitrary number of users. We then want to add 100 users to the account list...