I didn't expect this

[Ten_Mile_Hike]

I was bored today and just started playing in Lazarus trying to write stupid (obfuscated) code
for shits and giggles when all of a sudden THIS (indexing a hard coded string) WORKED.

Should I have been surprised that I am allowed to index a hard coded string?

Code: Pascal  [Select][+][-]

1. procedure TForm1.Button4Click(Sender: TObject);
2. var c:char; x:integer;
3. begin
4.  for x:=1 to Length('Mississippi') do
5.    if 'Mississippi'[x]='s' then Button4.caption:=Button4.caption+inttostr(X)+','
6. end;

[ASerge]

Should I have been surprised that I am allowed to index a hard coded string?

This is a long-standing opportunity. Such strings are usually defined as constants, which is why you didn't notice earlier.

[440bx]

Should I have been surprised that I am allowed to index a hard coded string?

Hard coded or otherwise, a string is an array of characters, indexing an array is completely normal.

It's just not obvious that the string is an array when it is hard coded.  For that reason, it's reasonable to be surprised but, it's completely logical.

[Khrys]

String indexing is a powerful operation 

Code: Pascal  [Select][+][-]

1. program Calculator;
2.  
3. begin
4.   WriteLn(Integer('eight plus eight'[0])); // Output: 16
5. end.

[Fibonacci]

String indexing is a powerful operation 

Code: Pascal  [Select][+][-]

1. program Calculator;
2.  
3. begin
4.   WriteLn(Integer('eight plus eight'[0])); // Output: 16
5. end.

Wow Get this:

Code: Pascal  [Select][+][-]

1. program Calculator;
2. begin
3.   WriteLn(Integer('2+2='[0])); // Output: 4
4. end.

[Bart]

Wow Get this:

Code: Pascal  [Select][+][-]

1. program Calculator;
2. begin
3.   WriteLn(Integer('2+2='[0])); // Output: 4
4. end.

Try that one (or the previous) with {$H+} 
(Or, to have fun with {$ZeroBasedStrings on})

Bart

[simone]

In fact, these fun examples are only valid for short strings, where the first character (position #0) of the underlying array contains the length of the string, as shown in:

https://www.freepascal.org/docs-html/current/prog/progsu160.html#x204-2140008.2.7