What does this error mean and how do I fix?

[VinDerKlaus]

Hello Friends,

My Form's caption is "[Tool Window] PATH". I try to get PATH part using GetPart function and assign result to string:

Code: Pascal  [Select][+][-]

1. PathStr := GetPart(['] '], [], Form1.Caption, false, false);

The output should be "PATH", but instead, I get error message:

Can't take address of constant expressions

How to repair this?

[winni]

Hi!

Use an intermediate string:

Code: Pascal  [Select][+][-]

1. var
2. s : String;
3. ....
4. s := Form1.Caption;
5. PathStr := GetPart(['] '], [], s, false, false);
6.  
7.  

Winni

[VinDerKlaus]

Many thank you winni,

It works now.
I wonder why it does this?

[winni]

Hi!

The string in getPart is a var parameter.

You are not allowed  to pass properties as var parameter.

Form.Caption is a property.
So copy it intermediate to a string.
Then you can pass the string as var parameter.

Not so nice but that's the (today) syntax.

Winni

[Leledumbo]

Many thank you winni,

It works now.
I wonder why it does this?

It traces waaaaay back to more than 10 years ago: https://wiki.freepascal.org/User_Changes_2.4.0#Treating_direct-mapped_properties_as_regular_fields