Program Kalkulator with Case

program kalkulator;
uses crt;
var
bil1, bil2:longint;
calc:char;
begin
clrscr;
write(‘bilangan pertama: ‘); readln(bil1);
write(‘operasi(+,/,*,-): ‘); readln(calc);
write(‘bilangan kedua: ‘); readln(bil2);
case calc of
‘+’:write(‘hasilnya= ‘, bil1+bil2);
‘-‘:write(‘hasilnya= ‘, bil1-bil2);
‘*’:write(‘hasilnya= ‘, bil1*bil2);
‘/’:if bil2=0 then write(‘Error’) else
write(‘hasilnya= ‘, bil1/bil2);
end;
readln;
end.