while(true) loop trouble

[Michele Degges]

I'm trying to create a simple calculator that keeps prompting the user for input until the user enters the standard input ("number" "operator") and the operator = 'E'.

I know in java I'd just use a while(true) loop (as I did in here), but I get the error "true undeclared." I'm new to C and am not sure what I'm doing wrong .. thanks for any help!

Here is my code:

#include <stdio.h>
#include <stdlib.h>

main() {

  double num; double accum;
  char op;

  printf("Initialize your Accumulator with data of the form 'number' 'S' which sets the Accumulator \
to the value of your number\n");
  scanf("%f %c", &num, &op);

  while (1) {

    if (op == 'S') {
    accum = num;
}

    else if (op == '+') {
      accum = accum+num;
    }

    else if (op == '*') {
      accum = accum*num;
    }

    else if (op == '/') {
      accum = accum/num;
    }

    else if (op == '-') {
      accum = accum-num;
}

    else if ((num == 0) && (op == '/')) {
      printf("Can not divide by 0.\n");
}


    else if (op == '-') {
      accum = accum-num;
}

    else if ((num == 0) && (op == '/')) {
      printf("Can not divide by 0.\n");
}

    else if (op == 'E') {
      printf("Value in the Accumulator = %d \n", accum);
      printf("End of Calculations.\n");
      exit(EXIT_SUCCESS); /*exits program if user enters E*/
    }

    else {
      printf("Unknown operator.\n");
    }

    printf("Value in the Accumulator = %f \n", accum);
    scanf("%f %c", &num, &op);

  }