Blending data and logic

Blending data and logic#

Two different programming styles#

Imagine you want to write an application that checks if the entered food is one of the following vegetables or not:

  • carrot

  • beetroot

  • cabbage

Take 1
#include <stdio.h>
#include <string.h>

#define LINE_SIZE 30

char line[LINE_SIZE];

int main(void) {
  printf("I can help you with your diet.\n");
  printf("Enter the food: ");
  scanf("%s", line);
  if (strcmp(line, "carrot") == 0 || strcmp(line, "beetroot") == 0 ||
      strcmp(line, "cabbage") == 0)
    puts("✅ this is a vegetable.");
  else
    puts("❌ I don't know what this is.");
}
Take 2
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define LINE_SIZE 30
#define VEGETABLE_COUNT 3

char line[LINE_SIZE];
const char MESSAGE_WELCOME[] = "I can help you with your diet.\n"
                               "Enter the food: ";
const char KNOWN_VEGETABLES[][LINE_SIZE] = {"carrot", "beetroot", "cabbage"};
const char MESSAGE_POSITIVE[] = "✅ this is a vegetable.";
const char MESSAGE_NEGATIVE[] = "❌ I don't know what this is.";

int main(void) {
  printf(MESSAGE_WELCOME);
  scanf("%s", line);
  for (size_t i = 0; i < _Countof KNOWN_VEGETABLES; ++i)
    if (strcmp(line, KNOWN_VEGETABLES[i]) == 0) {
      puts(MESSAGE_POSITIVE);
      return EXIT_SUCCESS;
    }
  puts(MESSAGE_NEGATIVE);
}

  • char variable[][N] means a collection of strings, where for each string N characters are reserved. We will introduce this.

Activity 12

  1. Which differences do you notice regarding:

    • readability

    • structure, e.g., where which components of code is located

  2. How could this difference affect the programming experience?

Steps:

  1. 3 min think individually and discuss with your partner

Contents