Structures in C Language: Definition and Usage

In the C language, a structure (struct) is a user-defined data type that allows the combination of different types of data into a single entity. Structures can enhance the readability and maintainability of code, enabling us to organize data in a more logical manner. This article will provide a detailed introduction to structures in C language and demonstrate how to define and use structures through examples.

What is a Structure?

A structure is a technique that supports combining multiple different types of data into a single entity. In C language, you can define a new data type using the struct keyword. For example, a structure representing student information may include attributes such as name, age, and score.

1. Defining a Structure

To define a new structure, you can use the following syntax:

struct StructName {    DataType member1;     DataType member2;    // More members...};

Here is a specific example for defining a structure for student information:

#include <stdio.h>
// Define a structure for student information
struct Student {    char name[50]; // Name    int age;      // Age    float score;  // Score};

In this example, we created a new data type named Student that contains three fields: name, age, and score.

2. Creating Structure Variables

Once you have defined a structure, you can create corresponding variables to store specific information. For example:

int main() {    struct Student student1; // Declare a variable of type Student named student1
    return 0;}

3. Initialization and Assignment

You can initialize with default values at declaration or assign values later. Here are a few methods to initialize student1:

Initializing with Specified Values

int main() {    struct Student student1 = {"Alice", 20, 88.5}; // Declare and initialize
    printf("Name: %s\n", student1.name);    printf("Age: %d\n", student1.age);    printf("Score: %.2f\n", student1.score);
    return 0;}

Assigning Values Individually

If declared but not initialized, you can assign values one by one as follows:

int main() {    struct Student student1;
   // Assign values to each member       strcpy(student1.name, "Bob");     student1.age = 22;     student1.score = 92.5;
     printf("Name: %s\n", student1.name);     printf("Age: %d\n", student1.age);     printf("Score: %.2f\n", student1.score);
   return 0;}

Note that when assigning values to character arrays (like names), we need to use the standard library function strcpy().

Using Pointers to Structures

To handle memory more flexibly, you can use pointers that point to the address of such type objects. As shown below:

int main() {
	struct Student *ptrStudent;          // Declare a pointer to a Student type object 
	ptrStudent = &student1              
	printf("Name via pointer: %s\n", ptrStudent->name);   
	printf("Age via pointer: %d\n", ptrStudent->age);    
	printf("Score via pointer: %.2f\n", ptrStudent->score);    
	return 0;}

Here, the “arrow” operator (->) is used to access members of the structure through the pointer.

Conclusion

This article introduced the basic concept of Structures in C language, which are akin to simple composite data types. We explored how to design them, their various uses, and related behaviors, including initialization methods and how to utilize smart referencing to access structure features. This also illustrates techniques that greatly enhance the reusability of programming code when handling complex relationships! I hope this article helps you understand this very useful element in the C programming world—Structures!!!!!