Exercise6-4 programming in c - c

Question

Right now I am learning to program in c by reading the book "Programming in C, 3rd edition" by Stephen Kockan.
Exercise6-4 in the book is really giving me a headache. In the book it says:
Write a program that acts as a simple "printing" calculator.
The program should allow the user to type in expressions of the form
number operator
The following operatros should be recognized by the program:
'+' '-' '*' '/' 'S' 'E'
The S operator tells the program to set the "accumulator" to the
typed-in number. The E operator tells the program that execution is to
end. The arithmetic operations are performed on the content of the
accumulator with the number that was keyed in acting as the seconcd
operand.
Here is a link,to how i figured it out too.
Unfortunately it's in Objective-C(but is still the same exercise!), and I don't understand
Objective-C syntax.
UPDATE
This is what I have made so far:
// "Printing" Calculator
#include <stdio.h>
int main(void)
{
char operator;
float value, result, accumulator;
printf("Begin Calculations...\n\n");
operator = '0';
while ( operator != 'E')
{
scanf("%f %c", &value, &operator);
switch(operator)
{
case 'S':
accumulator = value;
printf("The accumulator = %f", accumulator);
break;
case '+':
result = accumulator + value;
printf("%f + %f = %f", accumulator, value, result);
break;
case '-':
break;
case '*':
break;
case '/':
break;
default:
printf("Unknown operator");
break;
}
}
printf("Calculations terminated");
return 0;
}
I can't figure out how to use the scanf() function, and read both a value for an operation and a value for the accumulator. Because those two thing may not be the same.

Answer 1

Here is your C code.
#include <stdio.h>
#include <conio.h>
int main (void)
{
int loop;
float value,
acc = 0;
char o;
printf ("Simple Printing Calculator Program\n\n");
printf ("\nKEY: \n+ Add \n- Subtract \n* Multiply \n/ Divide\n");
printf ("S Set Accumulator \nE End Program\n\n");
printf ("Enter a number and an operator, then press enter\n\n");
printf ("Type in your expression: ");
for ( loop=0 ; loop>-1; ++loop)
{
{
scanf ("%f %c", &value, &o);
if ( o == '+' )
{
acc = acc + value; printf ("\n%.2f\n",acc);
}
else if ( o == '-' )
{
acc = acc - value; printf ("\n%.2f\n",acc);
}
else if ( o == '*' )
{
acc = acc * value; printf ("\n%.2f\n",acc);
}
else if ( o == 'S' )
{
acc = value; printf ("\n%.2f\n",acc);
}
else if ( o == 'E' )
{
printf ("\nFinal Value: %.2f\n\nGoodbye!",acc); loop = loop + 1000;
}
else if ( o == '/' )
if ( value == 0 )
{
loop = loop - loop -100;
printf ("\nDivision by zero.\n");
}
else
{
acc = acc / value; printf ("\n%.2f\n", acc);
}
else
{
loop = loop -loop-100;
printf ("\nUnknown operator.\n");
}
}
getch ();
return 0;
}