num will always contain an integer because it’s an int. The real problem with your code is that you don’t check the scanf return value. scanf returns the number of successfully read items, so in this case it must return 1 for valid values. If not, an invalid integer value was entered and the num … Read more
I believe that should do what you need.
CONIN$ is the console input device. Normally, stdin is an open file handle to this, but if stdin is redirected for some reason, then using CONIN$ will allow you to get access to the console despite the redirection. Reference.
You can use System.in to read from the standard input. It works just like entering it from a keyboard. The OS handles going from file to standard input.
Alright, let’s elaborate with some simplified explanation about the Scanner class. It is a standard Oracle class which you can use by calling the import java.util.Scanner. So let’s make a basic example of the class: Now when you call Scanner input = new Scanner(System.in); you make a new object of the Scanner class (so you make a new “Scanner”) and you store … Read more
It depends on whether you want to do it in a line by line basis or as a full set. For the whole file into a vector of integers: If you want to deal in a line per line basis:
You can use Scanner class Import first : Then you use like this. Side note : If you are using nextInt() with nextLine() you probably could have some trouble cause nextInt() does not read the last newline character of input and so nextLine() then is not gonna to be executed with desired behaviour. Read more in how to solve it in this previous question Skipping nextLine … Read more
The cin.clear() clears the error flag on cin (so that future I/O operations will work correctly), and then cin.ignore(10000, ‘\n’) skips to the next newline (to ignore anything else on the same line as the non-number so that it does not cause another parse failure). It will only skip up to 10000 characters, so the code is assuming the user will … Read more
To read user input you can try the cmd module for easily creating a mini-command line interpreter (with help texts and autocompletion) and raw_input (input for Python 3+) for reading a line of text from the user. Command line inputs are in sys.argv. Try this in your script: There are two modules for parsing command line options: (deprecated since Python 2.7, use argparse instead) and getopt. If … Read more
Here you can see the nature of Scanner: double nextDouble() Returns the next token as a double. If the next token is not a float or is out of range, InputMismatchException is thrown. Try to catch the exception UPDATE CASE 1 I tried your code and there is nothing wrong with it. Your are getting that error … Read more