Strings

{$assertions on}

procedure Test_TruncString;
const
  _a: string[3] = 'haihai';
  _b: string[5] = 'baibai';
  res: string[9] = _a + ' ' + _b;
var
  a: string[3];
  b: string[5];
begin
  a := _a;
  b := _b;

  Assert(Length(a) = 3, 'Length(a)');
  Assert(Length(b) = 5, 'Length(b)');

  Assert(a[1] = 'h', 'a[1]');
  Assert(a[1] + b[2] + a[3] = a, 'a[1] + b[2] + a[3]');

  Assert(a = 'hai',   'a <> hai');
  Assert(b = 'baiba', 'b <> bai');

  Assert(a = a,  'a <> a');
  Assert(a <> b, 'a = b');

  Assert(a + b = 'haibaiba', 'a + b');
  Assert(b + a = 'baibahai', 'b + a');
  Assert(a + ' ' + b = res, 'res');

  a := b;
  Assert(a = 'bai', 'a <> _b');

  b := 'kai' + a;
  Assert(b = 'kaiba', 'b <> kaiba');
end;

procedure Test_ShortString;
const
  _a: shortstring = 'hai';
  _b: shortstring = 'bai';
  res: shortstring = _a + ' ' + _b;
var
  a, b: shortstring;
begin
  a := _a;
  b := _b;

  Assert(Length(a) = 3, 'Length(a)');
  Assert(Length(b) = 3, 'Length(b)');

  Assert(a[1] = 'h', 'a[1]');
  Assert(a[1] + b[2] + a[3] = a, 'a[1] + b[2] + a[3]');

  Assert(a = 'hai', 'a <> hai');
  Assert(b = 'bai', 'b <> bai');

  Assert(a = a,  'a <> a');
  Assert(a <> b, 'a = b');

  Assert(a + b = 'haibai', 'a + b');
  Assert(b + a = 'baihai', 'b + a');

  Assert(a + ' ' + b = res, 'res');
end;

procedure Test_AnsiString;
const
  _a: ansistring = 'hai';
  _b: ansistring = 'bai';
  res: ansistring = _a + ' ' + _b;
var
  a, b: ansistring;
begin
  a := _a;
  b := _b;

  Assert(Length(a) = 3, 'Length(a)');
  Assert(Length(b) = 3, 'Length(b)');

  Assert(a[1] = 'h', 'a[1]');
  Assert(a[1] + b[2] + a[3] = a, 'a[1] + b[2] + a[3]');

  Assert(a = 'hai', 'a <> hai');
  Assert(b = 'bai', 'b <> bai');

  Assert(a = a,  'a <> a');
  Assert(a <> b, 'a = b');

  Assert(a + b = 'haibai', 'a + b');
  Assert(b + a = 'baihai', 'b + a');

  Assert(a + ' ' + b = res, 'res');
end;

procedure Test_UnicodeString;
const
  _a: unicodestring = 'hai';
  _b: unicodestring = 'bai';
  res: unicodestring = _a + ' ' + _b;
var
  a, b: unicodestring;
begin
  a := _a;
  b := _b;

  Assert(Length(a) = 3, 'Length(a)');
  Assert(Length(b) = 3, 'Length(b)');

  Assert(a[1] = 'h', 'a[1]');
  Assert(a[1] + b[2] + a[3] = a, 'a[1] + b[2] + a[3]');

  Assert(a = 'hai', 'a <> hai');
  Assert(b = 'bai', 'b <> bai');

  Assert(a = a,  'a <> a');
  Assert(a <> b, 'a = b');

  Assert(a + b = 'haibai', 'a + b');
  Assert(b + a = 'baihai', 'b + a');

  Assert(a + ' ' + b = res, 'res');
end;

begin
  Test_TruncString();   WriteLn('TruncString   :: Passed');
  Test_ShortString();   WriteLn('ShortString   :: Passed');
  Test_AnsiString();    WriteLn('AnsiString    :: Passed');
  Test_UnicodeString(); WriteLn('UnicodeString :: Passed');
end.

Output:
TruncString   :: Passed
ShortString   :: Passed
AnsiString    :: Passed
UnicodeString :: Passed