C Program Structure Dynamic Memory Allocation

Comprehensive Collection of C Programming Examples

In this example, you will learn to store the information entered by the user using dynamic memory allocation.

To understand this example, you should be familiar with the followingC Programming LanguageTopic:

• C Pointers

• C Dynamic Memory Allocation

• Structure

This program requires the user to store the value of noOfRecords and dynamically allocate memory for the noOfRecords structure variable using the malloc() function.

Demonstration of dynamic memory allocation of structures

#include <stdio.h>
#include <stdlib.h>
struct course {
　　　　int marks;
　　　　char subject[30];
};
int main() {
　　　　struct course　*ptr;
　　　　int i, noOfRecords;
　　　　printf("Enter the number of records: ");
　　　　scanf("%d", &noOfRecords);
　　　　//memory allocation for noOfRecords structures
　　　　ptr = (struct course　*)malloc(noOfRecords　*　sizeof(struct course));
　　　　for (i = 0; i < noOfRecords;)　++i) {
　　　　　　　　printf("Please enter the subject and mark name:\n");
　　　　　　　　scanf("%s %d", (ptr　+　i)->subject, &(ptr　+　i)->marks);
　　　　}
　　　　printf("Display information:\n");
　　　　for (i = 0; i < noOfRecords;)　++i)
　　　　　　　　printf("%s	%d\n", (ptr　+　i)->subject, (ptr　+　i)->marks);
　　　　return 0;
}

Output Results

Enter the number of records:　2
Enter the names of the topic and tag separately:
Programming
22
Enter the names of the topic and tag separately:
Structure
33
Display Information:
Programming　　　　　　22
Structure　　　　　　　　33

Comprehensive Collection of C Programming Examples