Re: Searching a String, and counting occurrences of an Integer within the String

From:

kingbarsa <barry.kingwill@gmail.com>

Newsgroups:

comp.lang.c++.moderated

Date:

Thu, 12 Mar 2009 03:47:32 CST

Message-ID:

<6d35bc0e-07f3-46b4-b6b8-59a978c5ff18@33g2000yqm.googlegroups.com>

On Mar 10, 9:15 am, mzdude <jsa...@cox.net> wrote:

Rather than worry about individual spaces, let the string operator >> do
the heavy lifting for you.

size_t parse2(char const *buf)
{
    bool isFldAng = strstr(buf,"FLD ANG") != NULL;
    std::istringstream instring(buf);
    std::string token;
    std::vector<int> num;

    // by default the following line will skip white space
    // and token will be complete.
    while( instring >> token)
    {
       bool digit = isdigit(token[0]) != 0;
       if( digit)
          num.push_back(atoi(token.c_str()));
    }

    return num.size(); // counted number of ints

}

Thanks mzdude, this worked particularily well.

I then moved on and also used it in other areas where I was extracting
floats from strings, however interestingly (and I guess not
surprising) isdigit does not pick up a float of less than one written
as .5155, but will pick it up when written as 0.5144.

This can be an issue when one cannot control the input, as is the case
for me.

Anyway in my case the entire strings were floats so I did not need to
test for digits, and merely assigned them all to floats, hence I have
not worked out a fix. Will have to cross that bridge when I get to it.

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