ptest4.pll

来自「一个嵌入式系统的C代码」· PLL 代码 · 共 38 行

PROGRAM PTEST4 (INPUT, OUTPUT);

{--------------------------------------------------}
{ PLL/2 test program tests function return values  }
{       and nested functions calls.                }
{                                                  }
{ Author: Ron Chernich (sometime in 92)            }
{--------------------------------------------------}

VAR
  A, B, C, D : INTEGER;

FUNCTION Max4 (X1, X2, X3, X4 : INTEGER) : INTEGER;

  FUNCTION MAX2 (X1, X2 : INTEGER) : INTEGER;
  BEGIN {Max2}
    MAX2 := X2;
    IF X1 > X2 THEN
      Max2 := X1;
  END;

BEGIN {Max4}
  Max4 := Max2(Max2(x1, x2), Max2(x3, x4))
END;

BEGIN {main}
  REPEAT
    WRITE('Enter 4 numbers (0 to quit): ');
    READ(A#);
    IF (A > 0) THEN BEGIN
      READ(B#, C#, D#);
      WRITELN;
      WRITELN('The Largest is', max4(a, b, c, d)#);
      WRITELN
    END
  UNTIL A = 0
END.