69.C Program to Write a Sentence to a File

C Program to Write a Sentence to a File

In this example, you'll learn to write a sentence to a file using fprintf() statement.

To understand this example, you should have the knowledge of following C programming topics:

• C Programming Files I/O
• C Standard Library Functions

This program stores a sentence entered by user in a file.

#include <stdio.h>
#include <stdlib.h>  /* For exit() function */
int main()
{
   char sentence[1000];
   FILE *fptr;

   fptr = fopen("program.txt", "w");
   if(fptr == NULL)
   {
      printf("Error!");
      exit(1);
   }
   
   printf("Enter a sentence:\n");
   gets(sentence);

   fprintf(fptr,"%s", sentence);
   fclose(fptr);

   return 0;
}

Output

Enter sentence: 
I am awesome and so are files.

After termination of this program, you can see a text file program.txt created in the same location where this program is located. 

If you open and see the content, you can see the sentence: I am awesome and so are files.

In this program, a file is opened using opening mode "w".

In this mode, if the file exists, its contents are overwritten and if the file does not exist, it will be created.

Then, user is asked to enter a sentence. This sentence will be stored in file program.txt using fprintf() function.

Check out these related examples:

• C Program to Read a Line From a File and Display it
• C program to Reverse a Sentence Using Recursion
• C Program to Display its own Source Code as Output

68.C Program to Store Information Using Structures with Dynamically Memory Allocation

C Program to Store Information Using Structures with Dynamically Memory Allocation

In this example, you'll learn to store information using structures by allocation dynamic memory using malloc().

To understand this example, you should have the knowledge of following C programming topics:

• C Programming Pointers
• C Dynamic Memory Allocation
• C Programming Structure

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

Example: Demonstrate the Dynamic Memory Allocation for Structure

#include <stdio.h>
#include<stdlib.h>

struct course
{
   int marks;
   char subject[30];
};

int main()
{
   struct course *ptr;
   int i, noOfRecords;
   printf("Enter number of records: ");
   scanf("%d", &noOfRecords);

   // Allocates the memory for noOfRecords structures with pointer ptr pointing to the base address.
   ptr = (struct course*) malloc (noOfRecords * sizeof(struct course));

   for(i = 0; i < noOfRecords; ++i)
   {
       printf("Enter name of the subject and marks respectively:\n");
       scanf("%s %d", &(ptr+i)->subject, &(ptr+i)->marks);
   }

   printf("Displaying Information:\n");

   for(i = 0; i < noOfRecords ; ++i)
       printf("%s\t%d\n", (ptr+i)->subject, (ptr+i)->marks);

   return 0;
}

Output

Enter number of records: 2
Enter name of the subject and marks respectively:
Programming
22
Enter name of the subject and marks respectively:
Structure
33

Displaying Information:
Programming      22
Structure        33

Check out these related examples:

• C Program to Store Information(name, roll and marks) of a Student Using Structure
• C Program to Store Information of Students Using Structure
• C Program to Find Largest Number Using Dynamic Memory Allocation

67.C Program to Store Information of Students Using Structure

C Program to Store Information of Students Using Structure

This program stores the information (name, roll and marks) of 10 students using structures.

To understand this example, you should have the knowledge of following C programming topics:

• C Programming Arrays
• C Programming Structure

In this program, a structure, student is created.

This structure has three members: name (string), roll (integer) and marks (float).

Then, we created a structure array of size 10 to store information of 10 students.

Using for loop, the program takes the information of 10 students from the user and displays it on the screen.

Example: Store Information in Structure and Display it

#include <stdio.h>
struct student
{
    char name[50];
    int roll;
    float marks;
} s[10];

int main()
{
    int i;

    printf("Enter information of students:\n");

    // storing information
    for(i=0; i<10; ++i)
    {
        s[i].roll = i+1;

        printf("\nFor roll number%d,\n",s[i].roll);

        printf("Enter name: ");
        scanf("%s",s[i].name);

        printf("Enter marks: ");
        scanf("%f",&s[i].marks);

        printf("\n");
    }

    printf("Displaying Information:\n\n");
    // displaying information
    for(i=0; i<10; ++i)
    {
        printf("\nRoll number: %d\n",i+1);
        printf("Name: ");
        puts(s[i].name);
        printf("Marks: %.1f",s[i].marks);
        printf("\n");
    }
    return 0;
}

Output

Enter information of students: 

For roll number1,
Enter name: Tom
Enter marks: 98

For roll number2,
Enter name: Jerry
Enter marks: 89
.
.
.
Displaying Information:

Roll number: 1
Name: Tom
Marks: 98
.
.
.

Check out these related examples:

• C Program to Store Information(name, roll and marks) of a Student Using Structure
• C Program to Store Information Using Structures with Dynamically Memory Allocation
• C Program to Add Two Distances (in inch-feet) System Using Structures

66.C Program to Calculate Difference Between Two Time Periods

C Program to Calculate Difference Between Two Time Periods

In this example, you'll learn to calculate the difference between two time periods using user defined - differenceBetweenTimePeriod function.

To understand this example, you should have the knowledge of following C programming topics:

• C Programming User-defined functions
• C Programming Structure
• How to pass structure to a function in C programming?
• C Programming Structure and Pointer

Example: Calculate Difference Between Two Time Periods

#include <stdio.h>
struct TIME
{
  int seconds;
  int minutes;
  int hours;
};
void differenceBetweenTimePeriod(struct TIME t1, struct TIME t2, struct TIME *diff);

int main()
{
    struct TIME startTime, stopTime, diff;

    printf("Enter start time: \n");
    printf("Enter hours, minutes and seconds respectively: ");
    scanf("%d %d %d", &startTime.hours, &startTime.minutes, &startTime.seconds);

    printf("Enter stop time: \n");
    printf("Enter hours, minutes and seconds respectively: ");
    scanf("%d %d %d", &stopTime.hours, &stopTime.minutes, &stopTime.seconds);

    // Calculate the difference between the start and stop time period.
    differenceBetweenTimePeriod(startTime, stopTime, &diff);

    printf("\nTIME DIFFERENCE: %d:%d:%d - ", startTime.hours, startTime.minutes, startTime.seconds);
    printf("%d:%d:%d ", stopTime.hours, stopTime.minutes, stopTime.seconds);
    printf("= %d:%d:%d\n", diff.hours, diff.minutes, diff.seconds);

    return 0;
}

void differenceBetweenTimePeriod(struct TIME start, struct TIME stop, struct TIME *diff)
{
    if(stop.seconds > start.seconds){
        --start.minutes;
        start.seconds += 60;
    }

    diff->seconds = start.seconds - stop.seconds;
    if(stop.minutes > start.minutes){
        --start.hours;
        start.minutes += 60;
    }

    diff->minutes = start.minutes - stop.minutes;
    diff->hours = start.hours - stop.hours;
}

Output

Enter start time:
Enter hours, minutes and seconds respectively: 12
34
55
Enter stop time:
Enter hours, minutes and seconds respectively:8
12
15

TIME DIFFERENCE: 12:34:55 - 8:12:15 = 4:22:40

In this program, user is asked to enter two time periods and these two periods are stored in structure variables startTime and stopTime respectively.

Then, the function differenceBetweenTimePeriod calculates the difference between the time periods and the result is displayed in main() function without returning it (Using call by reference technique).

Check out these related examples:

• C Program to Store Information Using Structures with Dynamically Memory Allocation
• C Program Swap Numbers in Cyclic Order Using Call by Reference
• C Program to Calculate the Power of a Number

65.C Program to Add Two Complex Numbers by Passing Structure to a Function

C Program to Add Two Complex Numbers by Passing Structure to a Function

This program takes two complex numbers as structures and adds them with the use of functions.

To understand this example, you should have the knowledge of following C programming topics:

• C Programming Structure
• How to pass structure to a function in C programming?

Example: Add Two Complex Numbers

#include <stdio.h>
typedef struct complex
{
    float real;
    float imag;
} complex;
complex add(complex n1,complex n2);

int main()
{
    complex n1, n2, temp;

    printf("For 1st complex number \n");
    printf("Enter real and imaginary part respectively:\n");
    scanf("%f %f", &n1.real, &n1.imag);

    printf("\nFor 2nd complex number \n");
    printf("Enter real and imaginary part respectively:\n");
    scanf("%f %f", &n2.real, &n2.imag);

    temp = add(n1, n2);
    printf("Sum = %.1f + %.1fi", temp.real, temp.imag);

    return 0;
}

complex add(complex n1, complex n2)
{
      complex temp;

      temp.real = n1.real + n2.real;
      temp.imag = n1.imag + n2.imag;

      return(temp);
}

Output

For 1st complex number
Enter real and imaginary part respectively: 2.3
4.5

For 2nd complex number
Enter real and imaginary part respectively: 3.4
5
Sum = 5.7 + 9.5i

In this program, structures n1 and n2 are passed as an argument of function add().

This function computes the sum and returns the structure variable temp to the main() function.

Check out these related examples:

• C program to Find all Roots of a Quadratic equation
• C Program Swap Numbers in Cyclic Order Using Call by Reference
• C Program to Calculate the Power of a Number

64.C Program to Add Two Distances (in inch-feet) System Using Structures

C Program to Add Two Distances (in inch-feet) System Using Structures

This program takes two distances (in inch-feet system), adds them and displays the result on the screen.

To understand this example, you should have the knowledge of following C programming topics:

• C Programming Structure

Example: Program to add two distances in inch-feet system

#include <stdio.h>

struct Distance
{
    int feet;
    float inch;
} d1, d2, sumOfDistances;

int main()
{
    printf("Enter information for 1st distance\n");
    printf("Enter feet: ");
    scanf("%d", &d1.feet);
    printf("Enter inch: ");
    scanf("%f", &d1.inch);

    printf("\nEnter information for 2nd distance\n");
    printf("Enter feet: ");
    scanf("%d", &d2.feet);
    printf("Enter inch: ");
    scanf("%f", &d2.inch);


    sumOfDistances.feet = d1.feet+d2.feet;
    sumOfDistances.inch = d1.inch+d2.inch;

    // If inch is greater than 12, changing it to feet.

    if (sumOfDistances.inch>12.0)
    {
        sumOfDistances.inch = sumOfDistances.inch-12.0;
        ++sumOfDistances.feet;
    }

    printf("\nSum of distances = %d\'-%.1f\"",sumOfDistances.feet, sumOfDistances.inch);
    return 0;
}

Output

Enter information for 1st distance
Enter feet: 23
Enter inch: 8.6

Enter information for 2nd distance
Enter feet: 34
Enter inch: 2.4

Sum of distances = 57'-11.0"

In this program, a structure Distance is defined. The structure has two members inch (a float) and feet (an integer).

Two variables (d1 and d2) are created which stores two distances (in inch and feet). Then, the sum of two distances is stored in sumOfDistances structure and displayed on the screen.

Check out these related examples:

• C Program to Store Information of Students Using Structure
• C Program to Store Information(name, roll and marks) of a Student Using Structure
• C Program to Store Information Using Structures with Dynamically Memory Allocation

63.C Program to Store Information(name, roll and marks) of a Student Using Structure

C Program to Store Information(name, roll and marks) of a Student Using Structure

This program stores the information (name, roll and marks) of a student and displays it on the screen using structures.

To understand this example, you should have the knowledge of following C programming topics:

• C Programming Structure

In this program, a structure, student is created.

This structure has three members: name (string), roll (integer) and marks (float).

Then, a structure variable s is created to store information and display it on the screen.

Example: Store Information and Display it Using Structure

#include <stdio.h>
struct student
{
    char name[50];
    int roll;
    float marks;
} s;

int main()
{
    printf("Enter information:\n");

    printf("Enter name: ");
    scanf("%s", s.name);

    printf("Enter roll number: ");
    scanf("%d", &s.roll);

    printf("Enter marks: ");
    scanf("%f", &s.marks);


    printf("Displaying Information:\n");

    printf("Name: ");
    puts(s.name);

    printf("Roll number: %d\n",s.roll);

    printf("Marks: %.1f\n", s.marks);

    return 0;
}

Output

Enter information:
Enter name: Jack
Enter roll number: 23
Enter marks: 34.5
Displaying Information:
Name: Jack
Roll number: 23
Marks: 34.5

Check out these related examples:

• C Program to Store Information of Students Using Structure
• C Program to Store Information Using Structures with Dynamically Memory Allocation
• C Program to Add Two Complex Numbers by Passing Structure to a Function