How cut a string and convert it to a number

---

Hello,
I need your help, I have a variable $traffic.traffic with the string

56 Minuten via E37

I need the part ahead “Minuten” but as a number not as string.
I have tried it with a VariablesDevice and the following:

(subString($traffic.traffic, "[0-9][2\}"))

But first the result is an empty string and second it is a string not a number…

I am not so familiar with regular expression.Can you explain yours? Or try this "(\d{1,2}) "

said in How cut a string and convert it to a number:

(subString($traffic.traffic, “[0-9][2}”))

Try the following. I have tested this with the VariablesDevice and it works. It takes one or two digits at the beginning of the value (assuming there are no leading space or such).

subString("$traffic.traffic", "^\d\{1,2\}")

@mwittig and @Heizelmann
Thank you for your fast reponce and help.
Ok this works I became a string “56” back. But when I chose in the VariablesDevice Number I became an error message, that is it a string and not a number.
So I have two things to solve:

1. Change the String to a Number
2. Can I search for the space " " between 56 and Minuten so if it is 100 Minuten i get “100” and not “10”?

@V1per You don’t need to search for the space, simply change the {1,2} to {1,3} then up to three digits are matched.

Ok, but than I have a string "56 " if this is not a problem to convert it into a number this will work.

But I don’t now how to convert this into a number. I became no variable chown from this device in Pimatic.

@V1per I see. The error message is more or less a warning. The variable is evalated correctly and also can be used in numeric operation. Pimatic distinguish only between Expression variable and Value variable but internally checks if it is a number or a string.

Nevertheless this behaviour should be corrected by the developers.

@Heizelmann
Great, how you said, ignore the error message and it works.
Thank you!!!

@mwittig
The device works now how expected but my log were spamed with hundreds off error messages:

error [pimatic]: Got string value for attribute $FZ of VariablesDevice but attribute type is number

Can you please help me?

@V1per said in How cut a string and convert it to a number:

Can you please help me?

You should set the expression as part of the variables device! Don’t use a variable as this won’t get re-evaluated when the traffic value changes. If you still see the error try the following work-around:

max(0, subString("$traffic.traffic", "^\d\{1,2\}"))

@mwittig said in How cut a string and convert it to a number:

max(0, subString("$traffic.traffic", "^\d\{1,2\}"))

This don`t work now it shows “Unkown”.

And I have allready set the expression “Number” in the variables device and this device throws out this error messages, but it works.

@mwittig
That is strange now it don’t work anymore… I have changed back to:

subString("$traffic.traffic", "^\d\{1,3\}")

But now it says allways “Unknown” even after a restart of pimatic, what the hell is that?

For me it works with the workaround from @mwittig

max(0, subString("$traffic.traffic", "^\d\{1,3\}"))

The device looks like this ( @V1per maybe you check this)

    {
      "variables": [
        {
          "name": "travelTimeMinutes",
          "expression": "max(0,subString(\"$traffic.traffic\", \"^\\d\\{1,3\\}\"))",
          "type": "number"
        }
      ],
      "xAttributeOptions": [],
      "id": "travelVariables",
      "name": "travelVariables",
      "class": "VariablesDevice"
    }

@Heizelmann @mwittig

You are right the workaround works. I am on work, so I can only arrive pimatic with my phone. So I think I have set spaces " " after the end of the funktion and this was the reason why the “Unknown” appears.

Thanks a lot to you guys!