Empty string: Difference between revisions
→Pascal: expand revision 04670F: add Extended Pascal
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=={{header|Pascal}}==
''See also [[#Delphi|Delphi]] or [[#Free Pascal|Free Pascal]]''
{{works with|Extended Pascal}}
<lang pascal>program emptyString(output);
var
s: string(20);
begin
{ assigning an empty string }
s := '';
{ checking for an empty string }
writeLn( 'EQ(s, '''') :':20, EQ(s, ''):6);
writeLn( 'length(s) = 0 :':20, length(s) = 0:6);
{ checking that a string is not empty }
writeLn( 'NE(s, '''') :':20, NE(s, ''):6);
writeLn( 'length(s) > 0 :':20, length(s) > 0:6);
{ Beware: Only the string comparison functions (`EQ`, `NE`, etc.) take }
{ the string’s length into account. The symbolic `=` equal comparison }
{ operator, however, will pad operands with blanks to the same common }
{ length, and _subsequently_ compare individual string components. }
writeLn('!!! s = '' '' :':20, s = ' ':6);
{ If you want to perform the empty string check with an `=` comparison, }
{ you will need to call `trim` (remove trailing blanks) first. }
writeLn('trim(s) = '''' :':20, trim(s) = '':6)
end.</lang>
{{out}}
EQ(s, '') : True
length(s) = 0 : True
NE(s, '') : False
length(s) > 0 : False
!!! s = ' ' : True
trim(s) = '' : True
=={{header|Perl}}==
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