Write('?') end; Procedures and functions Pascal structures programs into procedures and functions. Generally, a procedure is used for its side effects, whereas a function is used for its return value. program Printing; var i : integer; procedure PrintAnInteger(j : integer); begin ... end; function triple(const x: integer): integer; begin triple := x * 3 end; begin { main program } ... PrintAnInteger(i); PrintAnInteger(triple(i)) end. Procedures and functions can be nested to any depth, and the 'program' construct is the logical outermost block. By default, parameters are passed by value. If 'var' precedes a parameter's name, it is passed by reference. Each procedure or function can have its own declarations of goto labels, constants, types, variables, and other procedures and functions, which must all be in that order. This ordering requirement was originally intended to allow efficient single-pass compilation. However, in some dialects (such as Delphi) the strict ordering requirement of declaration sections has been relaxed. Semicolons as statement separators Pascal adopted many language syntax features from the ALGOL language, including the use of a semicolon as a statement separator. This is in contrast to other languages, such as PL/I and C, which use the semicolon as a statement terminator. No semicolon is needed before the end keyword of a record type declaration, a block, or a case statement; before the until keyword of a repeat statement; and before the else keyword of an if statement. The presence of an extra semicolon was not permitted in early versions of Pascal. However, the addition of ALGOL-like empty statements in the 1973 Revised Report and later changes to the language in ISO 7185:1983 now allow for optional semicolons in most of these cases. A semicolon is still not permitted immediately before the else keyword in an if statement, because the else follows a single statement, not a statement sequence. In the case of nested ifs, a semicolon cannot be used to avoid the dangling else problem (where the inner if does not have an else, but the outer if does) by putatively terminating the nested if with a semicolon – this instead terminates both if clauses. Instead, an explicit begin...end block must be used. Resources Compilers and interpreters Several Pascal compilers and interpreters are available for general use: Delphi is Embarcadero's (formerly Borland/CodeGear) flagship rapid application development (RAD) product. It uses the Object Pascal language (termed 'Delphi' by Borland), descended from Pascal, to