what is cin?

This is a discussion on what is cin? within the C++ Programming forums, part of the General Programming Boards category; hello i started to learn in this site and i don't understend what is the commend cin please help me...

  1. #1
    gilad
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    Question what is cin?

    hello
    i started to learn in this site and i don't understend what is the commend cin please help me

  2. #2
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    Inreasonably practical terms cin is the "command" to take information from the standard input source (usually the keyboard), store the information in a designated section of memory (the variable you specify), and (usually) display the information on the standard display source (usually the monitor screen). In a more technical sphere it is a predeclared global instance of the istream class, but there is no reason to get technical at your stage of the game.

  3. #3
    Guest Sebastiani's Avatar
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    Inreasonably practical terms cin is the "command" to take information from the standard input source (usually the keyboard), store the information in a designated section of memory (the variable you specify), and (usually) display the information on the standard display source (usually the monitor screen). In a more technical sphere it is a predeclared global instance of the istream class, but there is no reason to get technical at your stage of the game.
    More specifically, cin is a function which exploits two major C++ mechanisms:
    1) Overloaded operator.
    So you don't have to do 'cin(input);', instead you do 'cin >> input;'
    2) Overloaded parameters.
    'cin' is actually several functions, each written to accept a given datatype( one for int's, one for char*, etc, etc.

    cin does NOT display to the moniter. This is handled by the operating sytem thru the keyboard...
    Code:
    bool fun(bool value)
    {
        return std::pow(std::exp(1), std::complex<float>(0, 1) 
        * std::complex<float>(std::atan(1)*(1 << (value + 2))))
        .real() > 0;
    }

  4. #4
    Skunkmeister Stoned_Coder's Avatar
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    More specifically, cin is a function
    No it isn't. cin is an object. As has already been said it is a predeclared instance of istream.
    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
    Fingerstyle Guitarist taylorguitarman's Avatar
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    It's an input stream.
    I always called it console in (cin).
    Then it's opposite console out (cout).
    That keeps things simple.

  6. #6
    Hamster without a wheel iain's Avatar
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    its an input stream, it is a predefined instance of an object and if i remember correctly it is also buffered.
    Monday - what a way to spend a seventh of your life

  7. #7
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    Thank guy now can i get an example on how to use the cin command

  8. #8
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    Quote Originally Posted by Sixolile View Post
    Thank guy now can i get an example on how to use the cin command
    Code:
    cout << "How old are you?\n";
    int age;
    cin >> age;
    cout << "Ok, now i know you are " << age << " years old." << endl;
    Now in age variable you have value you entered in console.
    Last edited by kargo; 03-07-2011 at 11:10 AM.

  9. #9
    Programming Wraith GReaper's Avatar
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    I'm losing it! Is the year 2002?
    Devoted my life to programming...

  10. #10
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    Quote Originally Posted by Sixolile View Post
    Thank guy now can i get an example on how to use the cin command
    Now, after 9 years of trying to understand what the 'cin' command is, he/she wants an example. I'm wondering if in the next 9 years he/she will come back asking about cout. Good luck anyway.
    I never put signature, but I decided to make an exception.

  11. #11
    &TH of undefined behavior Fordy's Avatar
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    Closed. Please dont bump old threads

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