Say I get user input. If what they type in is not already in the array(how do I check an array?), add it to the array. And vice versa how do I remove something from an array given the user input.
Example:
string teams[] = {"St. Louis,","Dallas","Chicago,","Atlanta,"};
cout <<"What is the name of the city you want to add?" << endl;
cin >> add_city;
cout <<"What is the name of the city you want to remove?" << endl;
cin >> remove_city;
The size of built-in arrays is immutable: You can neither remove elements not can you add any. I would recommend using a std::vector<std::string>, instead: Adding elements to a std::vector<T> can, e.g., be done using push_back(). To remove an element you would locate an element, e.g., using std::find(), and then use erase() to remove it.
If you need to use built-in arrays (although I don't see any good reason for this), you'd allocate an array on the heap using new std::string[size] and maintain its size, appropriately releasing memory at opportune times using delete[] array;.
Using an array, you could treat empty array cells with a char* such as "EMPTY". To find an item you search through the array , and find to "replace" or add it.
const char * Empty = "EMPTY";
cout << "Please enter a city you want to add:"
cin >> city;
for(int i = 0; i < Arr_Size; i++) //variable to represent size of array
{
if(Arr[i] == Empty) //check for any empty cells you want to add
{
//replace cell
}
else if(i == Arr_Size-1) //if on last loop
cout << "Could not find empty cell, sorry!";
}
As for removing a cell:
cout << "Please enter the name of the city you would like to remove: ";
cin >> CityRemove;
for(int i = 0; i < Arr_Size; i++)
{
if(Arr[i] == CityRemove)
{
Arr[i] = Empty; //previous constant to represent your "empty" cell
}
else if(i == Arr_Size - 1) //on last loop, tell the user you could not find it.
{
cout << "Could not find the city to remove, sorry!";
}
}
Printing the array while skipping the 'empty' cells //Printing the array
for(int i = 0; i < Arr_Size; i++)
{
if(Arr[i] != Empty) //if the cell isnt 'empty'
{
cout << Arr[i] << endl;
}
}
But i do agree using a vector would be a much more efficient approach, this is simply a creative approach to get your mind thinking.
""?Arr as std::vector<std::string> Arr;... you should show that. string Arr[] would not work because there's no size method for built-in arrays.To add information to an array, you could do something like this:
for (int i = 0; i < 10; i++)
{
std::cout << "Please enter the city's name: " << std::endl;
std::getline(cin, myArray[i]);
}
I'm not sure what you mean by removing something from an array. Do you want to set the element's value to 0, which would result in something like {"City 1", "City 2", 0, "City 3}. Or do you want to remove it from the array and move the other elements to fill its space, which would result in something like {"City 1", "City 2", "City 3"}?
string, not const char*, so I'm not sure that having nulls in the initializer list will work.
teamsarray. Also, as mentioned below, using[]doesn't make the array variable-length; it makes its length depend on the length of the initializer list, in this case 4. From that point on, it's the same as a fixed-length array.std::vectoris what you really want."St. Louis,"should be"St. Louis".