checking input

This is a discussion on checking input within the C++ Programming forums, part of the General Programming Boards category; what happens if the user is asked to input a number or even comes from a file and u wanna ...

  1. #1
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    checking input

    what happens if the user is asked to input a number or even comes from a file
    and u wanna check if the input is really numbers and not something liek 124a
    how would u check that
    isdigit wont work on it cuz it requires a character
    cheers

  2. #2
    Skunkmeister Stoned_Coder's Avatar
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    >>isdigit wont work on it cuz it requires a character

    try using a loop!
    Free the weed!! Class B to class C is not good enough!!
    And the FAQ is here :- http://faq.cprogramming.com/cgi-bin/smartfaq.cgi

  3. #3
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    my input is an int
    not a char array

  4. #4
    Skunkmeister Stoned_Coder's Avatar
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    you have 2 strategies.
    1) use member functions of ios to decide whether input is good.
    2) get all input as a string and parse what u want from it.

    look up ios::fail(),ios::bad(),ios::clear(),ios::good(), etc. in your helpfiles. For strategy 2 look up stringstreams.
    Free the weed!! Class B to class C is not good enough!!
    And the FAQ is here :- http://faq.cprogramming.com/cgi-bin/smartfaq.cgi

  5. #5
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    how would i use the ios::fail and ios::bad here
    i mean how would they be set if the int contains a character?

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