Counting number of digits in a variable

This is a discussion on Counting number of digits in a variable within the C Programming forums, part of the General Programming Boards category; Dear friends, I have an assignment to convert from binary to decimal... I know how to do it but only ...

  1. #1
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    Counting number of digits in a variable

    Dear friends,

    I have an assignment to convert from binary to decimal... I know how to do it but only thing is I need to know how many digits are stored in my variable, for example :

    110101

    so if somehow I know there is 6 numbers I can make my loop and convert it to decimal very easy.

    Thanks.

  2. #2
    spurious conceit MK27's Avatar
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    Frequently Quite Prolix dwks's Avatar
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    That's only if the variable is stored in a string. If it's stored in an int, you can use a combination of modulus (%) and division (/) in a loop to do the conversion and to figure out how many digits there are. Come to think of it, you can probably do it with just division.

    For example, to count the number of binary digits:
    Code:
    int number = 42;
    int digits = 0;
    while(number) {
        digits ++;
        number /= 2;
    }
    dwk

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    That should be

    Code:
    number /= 10
    not

    Code:
    number /= 2

  5. #5
    and the Hat of Guessing tabstop's Avatar
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    Quote Originally Posted by KBriggs View Post
    That should be

    Code:
    number /= 10
    not

    Code:
    number /= 2
    That should be
    Code:
    number /= 2;
    not
    Code:
    number /= 10;

  6. #6
    C++ Witch laserlight's Avatar
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    Unless one really wants to deal with negative integers, it may be better to use say, unsigned int, and initialise digits to:
    Code:
    unsigned int digits = number == 0;
    in order to account for the case where the number is 0.
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    Haha oops I was thinking in decimal

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