Using Case Statement with String - delphi

Question

Say i have a string
'SomeName'
and wanted the values return in a case statement. Can this bedone? Can strings be used in a case statement like so
Case 'SomeName' of
'bobby' : 2;
'tommy' :19;
'somename' :4000;
else
showmessage('Error');
end;

Answer 1

In Jcl library you have the StrIndex function StrIndex(Index, Array Of String) which works like this:
Case StrIndex('SomeName', ['bobby', 'tommy', 'somename']) of
0: ..code.. ;//bobby
1: ..code..;//tommy
2: ..code..;//somename
else
ShowMessage('error');
end.

Answer 2

The Delphi Case Statement only supports ordinal types. So you cannot use strings directly.
But exist another options like
build a function which returns a Integer (hash) based on a string
using generics and anonymous methods ( A generic case for strings)
using a function which receive an array of strings (Making a case for Strings, the sane way)
and so on.

Answer 3

#Daniel's answer pointed me in the right direction, but it took me a while to notice the "Jcl Library" part and the comments about the standard versions.
In [at least] XE2 and later, you can use:
Case IndexStr('somename', ['bobby', 'tommy', 'somename', 'george']) of
0: ..code..; // bobby
1: ..code..; // tommy
2: ..code..; // somename
-1: ShowMessage('Not Present'); // not present in array
else
ShowMessage('Default Option'); // present, but not handled above
end;
This version is case-sensitive, so if the first argument was 'SomeName' it would take the not present in array path. Use IndexText for case-insensitive comparison.
For older Delphi versions, use AnsiIndexStr or AnsiIndexText, respectively.
Kudos to #Daniel, #The_Fox, and #afrazier for most of the components of this answer.

Answer 4

Works on D7 and Delphi Seattle,
uses StrUtils (D7) system.Ansistring (Delphi Seattle)
case AnsiIndexStr(tipo, ['E','R'] ) of
0: result := 'yes';
1: result := 'no';
end;

Answer 5

I used AnsiStringIndex and works, but if you can convert to number without problems:
try
number := StrToInt(yourstring);
except
number := 0;
end;

Answer 6

try this it uses System.StrUtils
procedure TForm3.Button1Click(Sender: TObject);
const
cCaseStrings : array [0..4] of String = ('zero', 'one', 'two', 'three', 'four');
var
LCaseKey : String;
begin
LCaseKey := 'one';
case IndexStr(LCaseKey, cCaseStrings) of
0: ShowMessage('0');
1: ShowMessage('1');
2: ShowMessage('2');
else ShowMessage('-1');
end;
end;