How come this doesnt work?

[wysota]

I wrote some code that tries to extract an integer 100 out of this string:

"AB,SH#100 \r\n\0"

That's exactly what I want. Just try extracting it.[/QUOTE]

QString func(const QString &s){ return "100"; }

QString func(const QString &s){ return "100"; }

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I doubt that's what you want...

If you don't tell us what are the rules of extraction in general way, we can't possibly give you code (other than I have given above) to do it. You said "extract 100", so return "100" seems a fine way to do it.

[ShaChris23]

Hi,

Thanks for all the inputs. How about this:

A string contains many fields. Each field starts with a 2 ASCII characters followed by the # sign.

Each field is delimited by a comma.

The last field is terminated by "\r\n"

We need to extract the number ( int or float ) after the # sign.

e.g. "DV#1200.03,AB#34,SH#100\r\n\0"

So for example, if a user is interested in the field "SH", he has to

Extract the SH field out,
Chop off first 3 characters
Convert the remaining string to be a number.

I hope this is helpful. I might be wrong here...but I think there's a bug in the Qt's QstringList::filter() method.

Thanks!

[wysota]

I'd do:

float extractCmd(const QString &str, const QString &expected){
  if(expected.size()>2 || str.size()<4) return 0;
  QStringList commands = str.simplified().split(",");
  static QRegExp rx("([A-Z][A-Z])#([0-9]*\\.?[0-9]+)");
  foreach(QString cmd, commands){
    if(!rx.exactMatch(cmd))
      continue;
    if(rx.cap(1)==expected)
      return rx.cap(2).toFloat();
  }
}
 
QString str = "DV#1200.03,AB#34,SH#100\r\n\0";
float val = extractCmd(str, "SH");

float extractCmd(const QString &str, const QString &expected){
  if(expected.size()>2 || str.size()<4) return 0;
  QStringList commands = str.simplified().split(",");
  static QRegExp rx("([A-Z][A-Z])#([0-9]*\\.?[0-9]+)");
  foreach(QString cmd, commands){
    if(!rx.exactMatch(cmd))
      continue;
    if(rx.cap(1)==expected)
      return rx.cap(2).toFloat();
  }
}

QString str = "DV#1200.03,AB#34,SH#100\r\n\0";
float val = extractCmd(str, "SH");

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