How do I error check if the user is inputting letters and not numbers?
For example, if the user inputs "Lab.txt" I need to display an error message.
If they input "Lab2part2.txt" then this is correct and what I want.
I've found a lot of information online on how to error check for numbers or a single letter (EX: 1,2,3, etc. or 'A' 'B' 'C') but nothing for actual WORDS or maybe I should refer to it as a string of characters?
Is there any way to do this? Because my program requires I ask the user to input the name of the file. But the way my code is currently set up is even when the user inputs the wrong file name it still opens the file. I want to prevent this from happening so my thought was to error check user input.