select string from begin to third space character

[addr3ss]

Hello!
How can I select or copy the beginner part of a string from character 1 to third space character?
for example:
in "IN THE NAME OF GOD"
select from "I"(character 1) to "O"(third space character).

[howardpc]

You could learn how to use regular expressions.
Or you could roll your own little parsing function. Numerous ways to do that, such as

Code: [Select]

function CopyTo3rdSpace(aText: string): string;
const
  Space = ' ';
var
  len: integer;
  spaceCount: integer = 0;
  i: integer = 1;
begin
  len:=Length(aText);
  if (len < 7) then
    Exit('');
  pc:=PChar(aText);
  repeat
    if (aText[i] = Space) then
      Inc(spaceCount);
    Inc(i);
    if (spaceCount = 3) and (i <= len) then
      begin
        Result:=Copy(aText, 1, i);
        Exit;
      end;
until (i > len);
  Result:='';
end;


[taazz]

or use leftstr midstr and the rest of the rtl strutils.

[addr3ss]

You could learn how to use regular expressions.
Or you could roll your own little parsing function. Numerous ways to do that, such as

Code: [Select]

function CopyTo3rdSpace(aText: string): string;
const
  Space = ' ';
var
  len: integer;
  spaceCount: integer = 0;
  i: integer = 1;
begin
  len:=Length(aText);
  if (len < 7) then
    Exit('');
  pc:=PChar(aText);
  repeat
    if (aText[i] = Space) then
      Inc(spaceCount);
    Inc(i);
    if (spaceCount = 3) and (i <= len) then
      begin
        Result:=Copy(aText, 1, i);
        Exit;
      end;
until (i > len);
  Result:='';
end;


OK tnx worked.but I want to copy strings that has under 3 spaces completely and copy the beginner part of strings that has 3 spaces and above.

[jc99]

OK tnx worked.but I want to copy strings that has under 3 spaces completely and copy the beginner part of strings that has 3 spaces and above.

My Code would be:

Code: [Select]

function CopyTonthSpace(aText: string;MaxSpace:integer=3): string;
const
  Space = ' ';
var
  i: integer;
  PartStr: String;
  spacepos: SizeInt;
//  pc: PChar;
begin
  Result := '';
  // If no spaces to look for, copy string;
  if MaxSpace = 0 then
    begin
      spacepos :=0;
      result := aText;
    end
  else
  // Build result Word by Word
  for i := 1 to MaxSpace do
    begin
      PartStr :=RightStr(aText,length(atext)-length(result));
      spacepos := pos(space,PartStr);
      if spacepos <> 0 then
        result := result + copy(PartStr,1,spacepos)
      else
        begin
          result := atext;
          break;
        end;
    end;
  // Copy the char after the last space
  if Spacepos <> 0 then
    result := result + copy(PartStr,spacepos+1,1);
end;
Results:
  CopyTonthSpace('In the Name of God') := 'In the Name o'
  CopyTonthSpace('In my Name') := 'In my Name'
  CopyTonthSpace('In my Name',0) := 'In my Name'

[addr3ss]

OK.I changed the code to this and worked.

Code: [Select]

repeat
    if string[i]=space then
       Inc(spacecount);
    Inc(i);
    if (spacecount<3)and(i<=Length(string)) then begin
    Label2.Caption:=string;
    end
    else if (spacecount=3)and (i<=Length(string)) then
       begin
       Label2.Caption:=Copy(string,1,i);
       Exit;
       end;
  until (i>Length(string));

[jc99]

OK.I changed the code to this and worked.

That's OK, But your code has 2 problems.
first you should not name you variable after a pascal-basetype like string and integer. 
I put your code in a test-Function

Code: [Select]

function TestCode(aText: string;MaxSpace:integer=3): string;
// I assumed these variables are initialized here
const
  Space = ' ';
var i:integer=0;
    spacecount:integer=0;
begin
repeat
    if aText[i]=space then
       Inc(spacecount);
    Inc(i);
    if (spacecount<MaxSpace)and(i<=Length(aText)) then begin
    result:=aText;
    end
    else if (spacecount=MaxSpace)and (i<=Length(aText)) then
       begin
       result:=Copy(aText,1,i);
       Exit;
       end;
  until (i>Length(aText));
end;
And test it against:

Code: [Select]

  writeln(TestCode('In the Name of God'));
  writeln(TestCode('In the Name of God, maker of all'));
  writeln(TestCode('In my Name'));
  writeln(TestCode('In my Name ')+'<');
  writeln(TestCode('In my Name  ')+'<');
  writeln(TestCode('In my Name',0)); // you'd expect the whole test but you only get 'I'
  writeln(TestCode('In  my Name'));
  writeln(TestCode('')+'<'); // here you get a SIGSEGV
I assumed your string-variable is a string, then you get a Segmentation Fault (SIGSEGV)
if you use shortstring instead you don't get that fault but the line 2 output 'In the N' instead of 'In the Name o'

Better do a length-check before "aText[ i ]"

Code: [Select]

if length(aText) = 0 then
  begin
     result := aText;
     exit; // see next comment about exit.
  end;
or

Code: [Select]

if (length(aText) >0) and (aText[i]=space) then
You should use exit with care.
In your case, if you only want to go to the end of the repeat-until construct, use break instead of exit
so if you want to execute code after until, it's not affected by the string.

Have you thought of other Whitespaces like <tab> ?

[addr3ss]

OK.I changed the code to this and worked.

That's OK, But your code has 2 problems.
first you should not name you variable after a pascal-basetype like string and integer. 
I put your code in a test-Function

Code: [Select]

function TestCode(aText: string;MaxSpace:integer=3): string;
// I assumed these variables are initialized here
const
  Space = ' ';
var i:integer=0;
    spacecount:integer=0;
begin
repeat
    if aText[i]=space then
       Inc(spacecount);
    Inc(i);
    if (spacecount<MaxSpace)and(i<=Length(aText)) then begin
    result:=aText;
    end
    else if (spacecount=MaxSpace)and (i<=Length(aText)) then
       begin
       result:=Copy(aText,1,i);
       Exit;
       end;
  until (i>Length(aText));
end;
And test it against:

Code: [Select]

  writeln(TestCode('In the Name of God'));
  writeln(TestCode('In the Name of God, maker of all'));
  writeln(TestCode('In my Name'));
  writeln(TestCode('In my Name ')+'<');
  writeln(TestCode('In my Name  ')+'<');
  writeln(TestCode('In my Name',0)); // you'd expect the whole test but you only get 'I'
  writeln(TestCode('In  my Name'));
  writeln(TestCode('')+'<'); // here you get a SIGSEGV
I assumed your string-variable is a string, then you get a Segmentation Fault (SIGSEGV)
if you use shortstring instead you don't get that fault but the line 2 output 'In the N' instead of 'In the Name o'

Better do a length-check before "aText[ i ]"

Code: [Select]

if length(aText) = 0 then
  begin
     result := aText;
     exit; // see next comment about exit.
  end;
or

Code: [Select]

if (length(aText) >0) and (aText[i]=space) then
You should use exit with care.
In your case, if you only want to go to the end of the repeat-until construct, use break instead of exit
so if you want to execute code after until, it's not affected by the string.

Have you thought of other Whitespaces like <tab> ?

no.it is just space.would you give me the correct code with this result?i tested it and its worked but i dont know what i should do for better performance.

[addr3ss]

oh...yes,i readed your advice carefully and found out.tnx

[jc99]

no.it is just space.would you give me the correct code with this result?i tested it and its worked but i dont know what i should do for better performance.

What is wrong with the function I gave you ?

Code: [Select]

function CopyTonthSpace(aText: string;MaxSpace:integer=3): string;
const
  Space = ' ';
var
  i: integer;
  PartStr: String;
  spacepos: SizeInt;
//  pc: PChar;
begin
  Result := '';
  // If no spaces to look for, copy string;
  if MaxSpace = 0 then
    begin
      spacepos :=0;
      result := aText;
    end
  else
  // Build result Word by Word
  for i := 1 to MaxSpace do
    begin
      PartStr :=RightStr(aText,length(atext)-length(result));
      spacepos := pos(space,PartStr);
      if spacepos <> 0 then
        result := result + copy(PartStr,1,spacepos)
      else
        begin
          result := atext;
          break;
        end;
    end;
  // Copy the char after the last space
  if Spacepos <> 0 then
    result := result + copy(PartStr,spacepos+1,1);
end;


TestCases:

Code: [Select]

  writeln(CopyTonthSpace('In the Name of God'));
  writeln(CopyTonthSpace('In the Name of God, maker of all'));
  writeln(CopyTonthSpace('In my Name'));
  writeln(CopyTonthSpace('In my Name ')+'<');
  writeln(CopyTonthSpace('In my Name  ')+'<');
  writeln(CopyTonthSpace('In my Name',0));
  writeln(CopyTonthSpace('In  my Name'));
  writeln(CopyTonthSpace('')+'<');
are good, performance is still ok since you/I copy word-blocks and not single character.
Generally put function first, performance later. 

[jc99]

Is this somehow related to your .resx- problem ?

[addr3ss]

No.they are differents.

[jc99]

oh...yes,i readed your advice carefully and found out.tnx

Read also about
http://wiki.freepascal.org/fpcunit

So you could always test your units/functions/object/classes
To see that they keep working as expected.