typedef and struct
- C course
- Intermediate
- Lesson 106/116
- 4 min
Learn to give a struct a short name with typedef.
typedef and struct
typedef gives a new name to a type. Used with struct, it saves you from writing struct every time. Declaration: typedef struct { ... } Person;.
Example: typedef struct { char name[32]; int age; } Person;. From then on you write Person p; instead of struct Person p;. This shortens code and improves readability. The type name is defined once and used throughout the program with the short name. This pattern is the foundation of data abstraction in C and gives consistent type names in large projects.
The Person struct
A Person struct holds name and age fields together. After defining with typedef, declaring variables and accessing fields becomes easy.
Example: Person p = {"Ayşe", 25}; creates a person. p.name gives the name, p.age the age. printf("%s %d\n", p.name, p.age); prints both fields. Values in braces map to the struct fields in order. This is the standard C way to represent record-like data; each field carries one attribute.
Practice Write the Person struct
Define typedef struct { char name[32]; int age; } Person;. In main create Person p = {"Ayşe", 25};. Print with printf("%s %d\n", p.name, p.age);.
Starter code
#include <stdio.h>
// Define the Person struct with typedef
// Create a Person variable in main and print
int main(void) {
return 0;
}Sample solution
#include <stdio.h>
typedef struct {
char name[32];
int age;
} Person;
int main(void) {
Person p = {"Ayşe", 25};
printf("%s %d\n", p.name, p.age);
return 0;
}Expected output
Ayşe 25
Questions and answers
Review the lesson questions together with their answers. To test yourself, solve the lesson interactively.
1 What does typedef struct provide?
- Less memory usage
- Faster compilation
- Avoids writing struct every time Correct answer
- Automatic cleanup
Explanation: typedef avoids repeating the struct keyword.
2 Complete the Person variable
Person p = {"Ayşe", ____};Person p = {"Ayşe", 25};Explanation: Person p = {"Ayşe", 25}; creates the person.
3 Match the typedef struct parts
| Term | Meaning |
|---|---|
typedef |
Naming |
struct |
Struct definition |
Person |
Short name |
p.name |
Field access |