Modula-2 Reference

                             Beginners Version

Single Types

   * CARDINAL
   * INTEGER
   * CHAR: characterconstant: 'a' 
   * REAL
   * BOOLEAN: 
	values TRUE & FALSE
	operators NOT, AND, OR

Structured Types

   * ARRAY
        o variable declaration: VAR array1: ARRAY [1..20] OF CARDINAL;
        o element of array: array1[2] := 1;
        o special array: string (ARRAY OF CHARs)
             + assignment: str := "bla";
        o multidimensional array :
             + VAR matrix10by20: ARRAY [1..10] OF ARRAY[1..20] OF CARDINAL;
             + identical declaration:  VAR matrix10by20: ARRAY [1..10],
               [1..20] OF CARDINAL;
             + use: matrix10by20[5, 15] := 7; or matrix10by20[5][15] := 7;
   * RECORD
        o declaration:
             + VAR jan : RECORD
             +            name, firstName: ARRAY[1..35] OF CHAR;
             +            length: CARDINAL;
             +     END;
        o use: jan.name := "Lemeire";   jan.firstName := "Jan";

Operators

Operator 	Explanation
NOT, AND, OR	logical operators
=, #    	equals, different
<, >, >=, <=	relational operators



Control Statements

IF (a > 5) OR (b > 6) THEN      condition
    ...                        statements
ELSE                        optional
    ...                        statements
END;


WHILE NOT (i > 10) DO        condition
    statements...
END;


REPEAT
    statements...
UNTIL (i = 10);

FOR  i := 10 TO 0 BY -1 DO     By clause is optional
    statements...
END;

Procedures

   * WrLn;                                    skip to next line
   * cardinalVariable := RdCard();          read cardinal
   * WrCard(cardinalVariable, spaces);      write cardinal
   * readVariable := RdInt();
   * WrInt(intVariable, spaces);
   * RdStr(stringVariable);                 read string (variabele tussen
     de haakjes!!)
   * WrStr(stringVariable);                 write string to output
   * charVariable := RdChar();              !! 2 ENTER-tokens stay in input
     buffer, are read in the next time with a RdChar
        o RdLn;                             use this after RdChar to read
          the rest of the input and the ENTER-tokens
   * WrChar(charVariable);
   * realVariable := RdReal();               read real from user input
   * WrReal(realVariable, precision, spaces);  write real to output
     (precision: number of digits)
   * booleanVariable := RdBool();            ty pe "TRUE" and "FALSE"
   * WrBool(booleanVariable, spaces);