Typedef

Writing struct Employee everywhere gets tiring. typedef lets us create a shorter name for any type

#include <stdio.h>

typedef struct {
    char name[50];
    int shift;
    int tasks;
} Employee;

int main(void) {
    Employee e = {"op7", 2, 5};
    printf("%s: shift %d\n", e.name, e.shift);
    return 0;
}

Now we write Employee instead of struct Employee. Much cleaner. This is how most C codebases define their structs

The pattern is typedef existing_type new_name

#include <stdio.h>

typedef int Hours;
typedef char* Str;

int main(void) {
    Hours worked = 9999;
    Str name = "op7";
    printf("%d %s\n", worked, name);
    return 0;
}

We can give meaningful names to types. Hours is still an int underneath, but the name tells you what it represents

typedef really shines with function pointers (if you're curious) and by dropping the struct keyword. Here's the most common pattern you'll see in real code

#include <stdio.h>

typedef struct {
    int register_id;
    int value;
} Cell;

typedef struct {
    Cell first;
    int total;
} Bank;

void print_bank(Bank *b) {
    printf("Register: %d, Value: %d, Total: %d\n",
           b->first.register_id, b->first.value, b->total);
}

int main(void) {
    Bank b = {{0, 512}, 512};
    print_bank(&b);
    return 0;
}

Notice how we can use Cell inside Bank. Structs within structs: composition. This is how C programs build complex data structures without classes

Mission: Shift Performance Report

The shift supervisor wants a formatted report of the computing center's operator evaluations. Use typedef to define a clean struct and walk through the list.

1. Define a typedef struct named Operator with fields: name (char array), grade (int), rating (double)
2. Read from input a count n of operators, followed by n lines, each with name grade rating
3. Walk through them and print each in the format "Name - Grade X - Rating Y.YY"

Example

Input

3
op1 10 9.50
op2 11 8.20
op3 10 9.80

Output

op1 - Grade 10 - Rating 9.50
op2 - Grade 11 - Rating 8.20
op3 - Grade 10 - Rating 9.80

Example

Input

2
shift1 7 6.75
shift2 9 8.00

Output

shift1 - Grade 7 - Rating 6.75
shift2 - Grade 9 - Rating 8.00