Grade XII C-Programming

 

Review of C-Programming

C programming language and its features

      C is a versatile programming language known for its simplicity and portability. It combines low-level and high-level features, making it suitable for both system and application development. With a focus on structured programming, C allows the creation and testing of modules independently, promoting code organization. Its machine independence enables programs to run on various systems. C is fast, reliable, and facilitates easy program extension by adding new features.

1. Simple and easy to learn.
2. Machine-independent, allowing programs to run on different systems.
3. Combines features of both low-level and high-level languages.
4. Suitable for developing system and application programs.
5. Supports structural programming; modules can be prepared and tested separately.
6. Fast and reliable performance.
7. Programs can be easily extended by adding new features and operations.

 

File Handling in C

In C programming, file handling is essential for storing and retrieving data permanently in secondary storage. Unlike variables in RAM, files allow data to persist beyond program execution.

Opening a Data File

FILE *fptr;

fptr = fopen("filename", "mode");

- "w" : Write/store data in a file.

- "r" : Read/retrieve data from a file.

- "a" : Add/append data to an existing file.

Storing/ Writing Data

fprintf(fptr, "format specifiers", variables);

Example:

fprintf(fptr, "%s %s %d %d", name, disease, age, bedNumber);

Program Examples

1) Create a Datafile "patient.txt"

#include <stdio.h>

int main() {

    char name[10], disease[10];

    int age, bedNumber;

    FILE *fptr;

    fptr = fopen("patient.txt", "w");

    printf("Enter name, disease, age, and bed number: ");

    scanf("%s %s %d %d", name, disease, &age, &bedNumber);

    fprintf(fptr, "%s %s %d %d\n", name, disease, age, bedNumber);

    fclose(fptr);

    return 0;

}

2) Create a Datafile "student.txt" to store name and marks of 3 subject for user desired student.

#include <stdio.h>

int main() {

    char name[10];

    int class, marks1, marks2, marks3, num, i;

    FILE *fptr;

    fptr = fopen("student.txt", "w");

    printf("How many records? ");

    scanf("%d", &num);

    for (i = 1; i <= num; i++) {

        printf("Enter name, class, and 3 marks: ");

        scanf("%s %d %d %d %d", name, &class, &marks1, &marks2, &marks3);

        fprintf(fptr, "%s %d %d %d %d\n", name, class, marks1, marks2, marks3);

    }

    fclose(fptr);

    return 0;

}

3) Add/Append Data to "student.txt"

#include <stdio.h>

int main() {

    char name[10], ch[3];

    int class, marks1, marks2, marks3;

    FILE *fptr;

    fptr = fopen("student.txt", "a");

if (fptr == NULL) {

        printf("Error opening the file.\n");

        return 1;  // Exit the program with an error code

    }

    do {

        printf("Enter name, class, and 3 marks: ");

        scanf("%s %d %d %d %d", name, &class, &marks1, &marks2, &marks3);

        fprintf(fptr, "%s %d %d %d %d\n", name, class, marks1, marks2, marks3);

        printf("Press Y to continue: ");

        scanf("%s", ch);

    } while (ch[0] == 'Y' || ch[0] == 'y');

    fclose(fptr);

    return 0;

}

//Example 4 Read

#include <stdio.h>

int main() {

    char name[10];

    int class, marks1, marks2, marks3;

    FILE *fptr;

    fptr = fopen("student.txt", "r");

    if (fptr == NULL) {

        printf("Error opening the file.\n");

        return 1;  // Exit the program with an error code

    }

    printf("Name\tClass\tMarks1\tMarks2\tMarks3\n");

    while (fscanf(fptr, "%s %d %d %d %d", name, &class, &marks1, &marks2, &marks3) != EOF) {

        printf("%s\t%d\t%d\t%d\t%d\n", name, class, marks1, marks2, marks3);

    }

    fclose(fptr);

    return 0;

}

//Example 5 read

#include <stdio.h>

int main() {

    char name[10];

    int class, marks1, marks2, marks3;

    FILE *fptr;

    fptr = fopen("student.txt", "r");

    if (fptr == NULL) {

        printf("Error opening the file.\n");

        return 1;

    }

    printf("Passing Students:\n");

    printf("Name\tClass\tMarks1\tMarks2\tMarks3\n");

    while (fscanf(fptr, "%s %d %d %d %d", name, &class, &marks1, &marks2, &marks3) != EOF) {

        if (marks1 >= 40 && marks2 >= 40 && marks3 >= 40) {

            printf("%s\t%d\t%d\t%d\t%d\n", name, class, marks1, marks2, marks3);

        }

    }

    printf("\nFailing Students:\n");

    printf("Name\tClass\tMarks1\tMarks2\tMarks3\n");

    fclose(fptr);

    return 0;

}

//Example 6 read

#include <stdio.h>

int main() {

    char name[10];

    int class, marks1, marks2, marks3;

    FILE *fptr;

    fptr = fopen("student.txt", "r");

    if (fptr == NULL) {

        printf("Error opening the file.\n");

        return 1;

    }

    int passCount = 0;

    int failCount = 0;

    printf("Passing Students:\n");

    printf("Name\tClass\tMarks1\tMarks2\tMarks3\n");

    while (fscanf(fptr, "%s %d %d %d %d", name, &class, &marks1, &marks2, &marks3) != EOF) {

        if (marks1 >= 40 && marks2 >= 40 && marks3 >= 40) {

            printf("%s\t%d\t%d\t%d\t%d\n", name, class, marks1, marks2, marks3);

            passCount++;

        } else {

            failCount++;

        }

    }

    printf("\nNumber of Passing Students: %d\n", passCount);

    printf("Number of Failing Students: %d\n", failCount);

    fclose(fptr);

    return 0;

}