strings.pas
PROGRAM strings;
USES sysutils, Character;
VAR
str: string = 'hello pascal';
BEGIN
WRITELN(str); // hello pascal
WRITELN(str[1]); // h
WRITELN(str[1..5]); // hello
// length
WRITELN(LENGTH(str));
// 12
// built-ins
WRITELN(UPPERCASE(str)); // HELLO PASCAL
WRITELN(LOWERCASE(str)); // hello pascal
// conditionals
WRITELN(ISNUMBER(str[1])); // FALSE
WRITELN(ISLETTER(str[1])); // TRUE
WRITELN(ISUPPER(str[1])); // FALSE
WRITELN(ISLOWER(str[1])); // TRUE
END.