If else statement displaying both options.
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Thread: If else statement displaying both options.

  1. #1
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    Question If else statement displaying both options.

    Hi, I am new to coding and have a question with my if else statement. This is a VERY simple program that I have made something like in Javascript before, but when I do it in C++ it does not work correctly. It displays both the options. Here is my code.
    // Practice.cpp : Defines the entry point for the console application.
    //

    #include "stdafx.h"
    #include <iostream>

    using namespace std;

    int main()
    // Asking for a number
    {
    int x;
    cout << "Give me a number.";
    cin.ignore();
    cin >> x;
    if (x < 25)
    {
    cout << "That is a small number.";
    }
    else (x >= 25);
    {
    cout << "That is a big number!";
    }
    }

  2. #2
    GCDEF is offline Elite Member Power Poster
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    Re: If else statement displaying both options.

    Quote Originally Posted by Sensei Nacho View Post
    Hi, I am new to coding and have a question with my if else statement. This is a VERY simple program that I have made something like in Javascript before, but when I do it in C++ it does not work correctly. It displays both the options. Here is my code.
    // Practice.cpp : Defines the entry point for the console application.
    //

    #include "stdafx.h"
    #include <iostream>

    using namespace std;

    int main()
    // Asking for a number
    {
    int x;
    cout << "Give me a number.";
    cin.ignore();
    cin >> x;
    if (x < 25)
    {
    cout << "That is a small number.";
    }
    else (x >= 25);
    {
    cout << "That is a big number!";
    }
    }
    You either need else without the condition, or add an if after the else. By itself (x >= 25) doesn't do anything. Further, since you have a semi-colon after your (x >=25) statement, the big number part isn't even part of the condition. It will always output.

  3. #3
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    Re: If else statement displaying both options.

    OK thanks, but now it only displays "That is a small number."

  4. #4
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    Re: If else statement displaying both options.

    Quote Originally Posted by GCDEF View Post
    You either need else without the condition, or add an if after the else. By itself (x >= 25) doesn't do anything. Further, since you have a semi-colon after your (x >=25) statement, the big number part isn't even part of the condition. It will always output.
    Thanks but now it only displays "That is a small number.". What am I doing wrong?

  5. #5
    GCDEF is offline Elite Member Power Poster
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    Re: If else statement displaying both options.

    Post your current code.

  6. #6
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    Re: If else statement displaying both options.

    Quote Originally Posted by GCDEF View Post
    Post your current code.
    // Practice.cpp : Defines the entry point for the console application.
    //

    #include "stdafx.h"
    #include <iostream>

    using namespace std;

    int main()
    // Asking for a number
    {
    int x;
    cout << "Give me a number.";
    cin.ignore();
    cin >> x;
    if (x < 25)
    {
    cout << "That is a small number.";
    }
    else
    {
    cout << "That is a big number!";
    }
    }

  7. #7
    Arjay's Avatar
    Arjay is offline Moderator / MS MVP Power Poster
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    Re: If else statement displaying both options.

    In c++ always initialize your variables. Also step through your code or use trace statements to see what is wrong. Btw what does cin.ignore do?

  8. #8
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    Re: If else statement displaying both options.

    Before posting, please format your code properly and use code tags. Go advanced, select the code and click '#'.

    Arjay has given you the hint asking about cin.ignore().
    All advice is offered in good faith only. You are ultimately responsible for effects of your programs and the integrity of the machines they run on.

  9. #9
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    Re: If else statement displaying both options.

    What is the purpose of the following statement ?

    Code:
    cin.ignore();
    What does it do ? And how does it effect the input stream ? Hint: output the value of "x"
    after you read it in.

    Edit: Sorry ... I did not look at all the posts. I see that ignore() was already mentioned.

  10. #10
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    Re: If else statement displaying both options.

    Quote Originally Posted by Arjay View Post
    In c++ always initialize your variables. Also step through your code or use trace statements to see what is wrong. Btw what does cin.ignore do?
    What do these mean?

  11. #11
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    Re: If else statement displaying both options.

    Quote Originally Posted by 2kaud View Post
    Before posting, please format your code properly and use code tags. Go advanced, select the code and click '#'.

    Arjay has given you the hint asking about cin.ignore().
    How do I do this?

  12. #12
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    9

    Re: If else statement displaying both options.

    Quote Originally Posted by Philip Nicoletti View Post
    What is the purpose of the following statement ?

    Code:
    cin.ignore();
    What does it do ? And how does it effect the input stream ? Hint: output the value of "x"
    after you read it in.

    Edit: Sorry ... I did not look at all the posts. I see that ignore() was already mentioned.
    As far as I can tell, in a console program, it makes it so enter doesn't close the console.

  13. #13
    VictorN's Avatar
    VictorN is offline Super Moderator Power Poster
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    Re: If else statement displaying both options.

    Quote Originally Posted by Sensei Nacho View Post
    How do I do this?
    Begin with reading the Announcement: Before you post....
    Victor Nijegorodov

  14. #14
    Arjay's Avatar
    Arjay is offline Moderator / MS MVP Power Poster
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    Re: If else statement displaying both options.

    Quote Originally Posted by Sensei Nacho View Post
    As far as I can tell, in a console program, it makes it so enter doesn't close the console.
    When you don't understand what something means, try to look it up in msdn. Do a search in bing or google for "std::cin:ignore".

    In the results look for something that contains msdn in the url.

    The second link in the bing results is basic_istream::ignore which may not look promising, but it does have msdn... in the url.
    http://msdn.microsoft.com/en-us/library/3w23zf49.aspx

    A good place to start.

    Pay particular attention to the sample code at the bottom of the page - especially the output that is shown after the code snippet.

  15. #15
    Arjay's Avatar
    Arjay is offline Moderator / MS MVP Power Poster
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    Re: If else statement displaying both options.

    Quote Originally Posted by Sensei Nacho View Post
    What do these mean?
    Initialize your variables means to declare them and then set them. You can do this all in one step. In C++, initializing variables prevents a variable from starting out with garbage and it's a good practice to get into (because they are often a source of bugs).

    Code:
    int x;  // uninitialized variable it's anyone's guess what its starting value will be.
    
    int y = 0;  variable declared and initialized to 0

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