Problem with String Concatenation

[AlanJB]

Apologies if this is a long post for a simple problem, but I wanted to give as much info as possible.

This started as a simple diagnostic exercise to check that I was correctly getting the source paths of all 5 open tabs in the left explorer panel.

The script (note line 6 , beginning "$Paths...") is:

Code: [Select]

@var $Paths = "";
@var $n = 0;
for ( $n=1; $n<6; $n++ )
{
  MC.SetActiveTab PANEL=LEFT TAB={$n};
  $Paths += GetSourcePath() + "\r\n";
}
MessageBox ("Output",$Paths,0)

The Output, as expected, is:

Code: [Select]

C:\Alan\
C:\Zip\
C:\Tools\
C:\Temp\
C:\Users\Alan\

If I change line 6 to:  $Paths += $n + GetSourcePath() + "\r\n";  the output, NOT as expected, is:

Code: [Select]

12345

It seems everything after $n is ignored in the concatenation !?

If I change line 6 to:  $Paths += GetSourcePath() + " " + $n + "\r\n";  the output, again NOT as expected, is:

Code: [Select]

C:\Alan\ 1C:\Zip\ 2C:\Tools\ 3C:\Temp\ 4C:\Users\Alan\ 5

Once again, it seems everything after $n is ignored.  Is this expected behaviour?  Is there a workaround, or am I doing something wrong?

According to the documentation:  "Conversion from string to number and number to string are often done automatically, making it possible to concatenate a number variable or constant to a string."

TIA

Alan

[Mathias (Author)]

I think is because $n is a number, so when you do + it tries to do math

Normally num converts to string automatically. But that is not possible in all situations.

But you can force a number into a string

Code: [Select]

$Paths += numtostr($)n + GetSourcePath() + "\r\n";

[AlanJB]

I guessed that may be the case when further testing (after I posted) showed that if $n was the last argument in the concatenated string, it worked.

numtostring() works fine - thanks.

Luckily, no-one spotted my deliberate (ahem) mistake - the space in "MessageBox (", which will cause the function to fail, of course.  You need to make the script engine smarter to allow for programmers like me 

Thanks again.

Alan