C
Putting it together
Build a working CLI app with a menu loop.
Putting it together
In the final step we combine all pieces into a complete to-do CLI. Three functions (add_task, list_tasks, complete_task) and the struct Task array work together.
In this lesson we add a third task and complete the flow. This way the add, complete, list flow works end to end.
The menu loop idea
In a real CLI app the user picks from a menu: add task, list, complete or exit. A menu loop can be built with while and switch.
while (choice != 0) {
switch (choice) {
case 1: count = add_task(tasks, count, title); break;
case 2: list_tasks(tasks, count); break;
case 3: complete_task(tasks, id); break;
}
}
In this lesson we use a fixed flow instead of a menu: add, complete, add again, list.
Exercise Add the third task and complete the flow
In the code below add the line count = add_task(tasks, count, "Reading"); after the complete_task(tasks, 1); call. This runs the full three-task flow: add, add, complete, add again, list. Output should be 1 Shopping 1, 2 Sport 0 and 3 Reading 0.
Show example solution
#include <stdio.h>
#include <string.h>
struct Task {
int id;
char title[50];
int done;
};
int add_task(struct Task tasks[], int count, const char *title) {
tasks[count].id = count + 1;
strcpy(tasks[count].title, title);
tasks[count].done = 0;
return count + 1;
}
void list_tasks(struct Task tasks[], int count) {
for (int i = 0; i < count; i++) {
printf("%d %s %d\n", tasks[i].id, tasks[i].title, tasks[i].done);
}
}
void complete_task(struct Task tasks[], int id) {
tasks[id - 1].done = 1;
}
int main(void) {
struct Task tasks[10];
int count = 0;
count = add_task(tasks, count, "Shopping");
count = add_task(tasks, count, "Sport");
complete_task(tasks, 1);
count = add_task(tasks, count, "Reading");
list_tasks(tasks, count);
return 0;
}
Test yourself
-
Add the third task
count = add_task(tasks, count, ____); /* add third task */
Show answer
count = add_task(tasks, count, "Reading"); /* add third task */
-
Match functions
- add_task
- adding tasks
- list_tasks
- listing
- complete_task
- completing
- while
- menu loop
-
What is the best structure for a CLI menu loop?
- A struct definition
- Just printf
- A single if
- A while loop with switch
Show answer
A while loop with switch — A while loop gives repetition, switch gives selection.
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