++ndigit[c-'0'] || please explain.

This is a discussion on ++ndigit[c-'0'] || please explain. within the C Programming forums, part of the General Programming Boards category; Code: int c, ndigit[10]; while ((c = getchar()) != EOF) { if (c >= '0' && c <= '9') ++ndigit[c-'0']; ...

  1. #1
    Registered User xion's Avatar
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    ++ndigit[c-'0'] || please explain.

    Code:
    int c, ndigit[10];
    
    while ((c = getchar()) != EOF)
    {
            if (c >= '0' && c <= '9')
               ++ndigit[c-'0'];
    this is an excerpt from a code that counts digits and whitespaces.

    ive asked around about the c-'0' expression and theyre making c = 1. 1 = 49 in ascii. and 0 = 48 in ascii. therefore c-'0' = 1. ive got that much but what i do not understand is there are more than 10 different characters that can be entered upon input. why is "if (c >= '0' && c <= '9')" used in this program when there are more than 10 different characters that can be entered?

  2. #2
    ATH0 quzah's Avatar
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    That check rules out anything other than digits. If it is greater than '0' and less than '9', count it, otherwise ignore it.

    Quzah.
    Hope is the first step on the road to disappointment.

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