C Programming

Write a program in C to draw an eclipse on screen using graphics.h header file

In this program, we will draw an eclipse on screen having centre at mid of the screen. We will use ellipse functions of graphics.h header file to draw eclipse on screen. Below is the detailed descriptions of ellipse function.

void ellipse(int xCenter, int yCenter, int startAngle, int endAngle, int xRadius, int yRadius);

To draw a complete eclipse, we should pass start and end angle as 0 and 360 respectively.

C program to draw an eclipse using graphics

In this program we first initialize graphics mode, by passing graphics driver(DETECT), default graphics mode and specifies the directory path where initgraph looks for graphics drivers (*.BGI). First of all we will calculate the center co-ordinates of eclipse which is the center of screen bu calling getmaxx and getmaxy function. Then we draw full eclipse by calling ellipse function.

#include<stdio.h>
#include<graphics.h>
#include<conio.h>
 
int main(){
   int gd = DETECT,gm;
   int x ,y;
   initgraph(&gd, &gm, "X:\\TC\\BGI");
   /* Initialize center of ellipse with center of screen */
   x = getmaxx()/2;
   y = getmaxy()/2;
 
   outtextxy(x-100, 50, "ELLIPSE Using Graphics in C");
   /* Draw ellipse on screen */
   ellipse(x, y, 0, 360, 120, 60);
 
   getch();
   closegraph();
   return 0;
}

Program Output

In this program, we will draw a bar graph on screen. Here, we will use line, setfillstyle and bar functions of graphics.h header file to draw horizontal and vertical axis and bars on screen.

void line(int x1, int y1, int x2, int y2);

It draws a line from (x1, y1) to (x2, y2).

void setfillstyle(int pattern, int color);

It sets the current fill pattern and fill color.

void bar(int xTopLeft, int yTopLeft, int xBottomRight, int yBottomRight);

bar function draws a rectangle and fill it with current fill pattern and color.

C program to draw bar graph using graphics

#include <graphics.h>
#include <conio.h>
  
int main() {
   int gd = DETECT, gm;
   initgraph(&gd, &gm, "X:\\TC\\BGI");
 
   settextstyle(BOLD_FONT,HORIZ_DIR,2);
   outtextxy(275,0,"BAR GRAPH");
 
   setlinestyle(SOLID_LINE,0,2);
   /* Draw X and Y Axis */
   line(90,410,90,50);
   line(90,410,590,410);
   line(85,60,90,50);
   line(95,60,90,50);
   line(585,405,590,410);
   line(585,415,590,410);
 
   outtextxy(65,60,"Y");
   outtextxy(570,420,"X");
   outtextxy(70,415,"O");
   /* Draw bars on screen */
   setfillstyle(XHATCH_FILL, RED);
   bar(150,80,200,410);
   bar(225,100,275,410);
   bar(300,120,350,410);
   bar(375,170,425,410);
   bar(450,135,500,410);
 
   getch();
   closegraph();
   return 0;
}

Program Output

• In this tutorial, we will learn about array of structure variables in c programming language. Declaration of structure array and accessing structure array element using subscript.

A structure in C programming language is used to store set of parameters about an object/entity. We sometime want to store multiple such structure variables for hundreds or objects then Array of Structure is used.

Both structure variables and in-built data type gets same treatment in C programming language. C language allows us to create an array of structure variable like we create array of integers or floating point value. The syntax of declaring an array of structure, accessing individual array elements and array indexing is same as any in-built data type array.

Declaration of Structure Array in C

struct Employee
{
    char name[50];
    int age;
    float salary;
}employees[1000];
or
struct Employee employees[1000];

In above declaration, we are declaring an array of 1000 employees where each employee structure contains name, age and salary members. Array employees[0] stores the information of 1st employee, employees[1] stores the information of 2nd employee and so on.

Accessing Structure Fields in Array
We can access individual members of a structure variable as

array_name[index].member_name

For Example

employees[5].age

C Program to Show the Use of Array of Structures

In below program, we are declaring a structure “employee” to store details of an employee like name, age and salary. Then we declare an array of structure employee named “employees” of size 10, to store details of multiple employees.

#include <stdio.h>
#include <conio.h>
 
struct employee {
    char name[100];
 int age;
 float salary;
};
 
int main(){
   struct employee employees[10];
   int counter, index, count, totalSalary;
    
   printf("Enter Number of Employees\n");
   scanf("%d", &count);
    
   /* Storing employee detaisl in structure array */
   for(counter=0; counter<count; counter++){ 
       printf("Enter Name, Age and Salary of Employee\n");
       scanf("%s %d %f", &employees[counter].name, 
           &employees[counter].age, &employees[counter].salary);
   }
    
   /* Calculating average salary of an employee */
   for(totalSalary=0, index=0; index<count; index++){
       totalSalary += employees[index].salary;
   }
    
   printf("Average Salary of an Employee is %f\n", 
       (float)totalSalary/count);
 
   getch();
   return 0;
}

Output

Enter Number of Employees
3
Enter Name, Age and Salary of Employee
Jack 30 100
Enter Name, Age and Salary of Employee
Mike 32 200
Enter Name, Age and Salary of Employee
Nick 40 300
Average Salary of an Employee is 200.000000

isupper() function checks whether a character is uppercase alphabet(A-Z) or not.

Function prototype of isupper

int isupper(int c);

Function isupper() takes a character as input in form of an integer. When we pass a value of type char to isupper() function, corresponding ASCII value of that character is passed.

Return value of isupper

If passed character is a uppercase character, then isupper function returns non-zero(true) integer otherwise 0(false).

C program using isupper function

The following program is to check whether a character is uppercase character or not.

#include <stdio.h>
#include <ctype.h>
#include <conio.h>
 
int main(){
    char string[] = "Aa.1";
    int index = 0;
     
    while(string[index] != '\0'){
        if(isupper(string[index])){
            printf("'%c' is a uppercase character\n", string[index]);
        } else {
            printf("'%c' is not a uppercase character\n", string[index]);
        }
        index++;
    }
     
    getch();
    return 0;
}

Output

'A' is a uppercase character
'a' is not a uppercase character
'.' is not a uppercase character
'1' is not a uppercase character

Write a program in C to draw 3D bar chart on screen using graphics.h header file

In this program, we will draw a 3D bar graph on screen. Here, we will use line, setfillstyle and bar3d functions of graphics.h header file to draw horizontal and vertical axis and bars on screen.

void line(int x1, int y1, int x2, int y2);

It draws a line from (x1, y1) to (x2, y2).

void setfillstyle(int pattern, int color);

It sets the current fill pattern and fill color.

void bar3d(int xTopLeft, int yTopLeft, int xBottomRight, int yBottomRight, int depth, int topFlag);

bar3d function draws a 3D cuboid and fill front facing surface with current fill pattern and color.

C program to draw 3D bar graph using graphics

#include <graphics.h>
#include <conio.h>
  
int main() {
   int gd = DETECT, gm;
   initgraph(&gd, &gm, "C:\\TC\\BGI");
 
   settextstyle(BOLD_FONT,HORIZ_DIR,2);
   outtextxy(275,0,"3D BAR GRAPH");
 
   setlinestyle(SOLID_LINE,0,2);
   /* Print X and Y Axis */
   line(90,410,90,50);
   line(90,410,590,410);
   line(85,60,90,50);
   line(95,60,90,50);
   line(585,405,590,410);
   line(585,415,590,410);
 
   outtextxy(65,60,"Y");
   outtextxy(570,420,"X");
   outtextxy(70,415,"O");
 
   /* Print 3D bars */
   setfillstyle(XHATCH_FILL, RED);
   bar3d(150,80,200,410, 15, 1);
   bar3d(225,100,275,410, 15, 1);
   bar3d(300,120,350,410, 15, 1);
   bar3d(375,170,425,410, 15, 1);
   bar3d(450,135,500,410, 15, 1);
 
   getch();
   closegraph();
   return 0;
}

Program Output