I have a homework assignment that requires that I sort an array of Accounts that contains strings for ID, PIN, and balance. I believe that I need to sort the array based on the ID. And then I have to verify the ID that the user inputs to the accounts that have been read in using ifStream. How do I use Binary Search to compare strings?

there are several examples and tutorials. I suggest you use a structure to hold the data for one account then put the structures in an array. That helps keep all the data together when sorting and searching. The actual algorithm you are looking for is almost the same as shown in the link I posted. Just change the comparison to use string compares instead of integer compares.

Thanks