Calculator - Programmers Heaven

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# Calculator

Posts: 9Member
so i have this project for school to create a pascal program. i was thinking of making a calculator which can do stuff like cosine and all that stuff. like a scientific calculator. The program has to use crt because thats all weve learnt so far. im not an expert at pascal but i still understand some stuff like loops and menus and such. would the only way to make this be a menu saying stuff like 1) Plus, 2) Minus and so on? or is it possible to just enter in a whole line like 1+4 and then you get the answer? all i want is the basic layout of the program to start off with and then i can build it up.

• Posts: 268Member
This is a simple calculator ( addition supported only ):[code][color=Blue]function calculate(s:string):string;
var sl:byte absolute s; {lenght of s}
a1,a2:real;
i:byte;
function to_val(si:string):real;
var r:real;
c:integer;
begin
val(si,r,c);
to_val:=r;
end;
begin
if sl>2 then begin {must at least 3 char long }
if i=0 then s:='Syntax error' else begin
a1:=to_val(copy(s,1,i-1));
a2:=to_val(copy(s,i+1,sl-i));
str(a1+a2:6:4,s);
end;
end;
calculate:=s;
end;

begin
writeln(calculate('145+345'));
end.[/color][/code]