Find Area Of A Circle

Find area of circle program in C

This is our first program in C programming language. This C program will print the text

“Hello World!” on the console output screen. In this post we will learn how to 

write a C Program and explore each statements in this C Program and many more.

                                                                 

/*area of circle*/

#include<stdio.h>
#include<conio.h>

int main()

{
     int  radius;
     float area;
      printf("Enter the radius of circle:");
         scanf("%d",&radius);

       area=3.14*radius*radius;

     printf("Area  of circle is=%f",area);
     getch();

     return(0);

}

Output: 

Enter the radius of circle :5
Area of circle is=78.500000

Explanation Of Each Statements In The Program:-

To learn any programming language, practical is must important than others factors. First of

all we learn and understand the language and then we implements, each things related to 

the language and explore about it. After all we are interested in making products (Software)

by using that language.

Every programmer and learner first of all print Hello world! Program while they start learning

a programming language. So we are going to print Hello World! on the console output

screen.

#0: \*First program in C to print Hello World! text the console output screen */

This statement are called comment. We write comment in C programming language by using /* */ this symbols and writes somethings message within these symbols. We write the

comment about program and statement of that program to remember written statements and logic after sometimes. The comments have lot’s advantages in the programming, we

will learn more about comments in the others post.

#1: #include <stdio.h>

stdio.h is called header file which contains declarations of standard input, output related

library functions of the C programming language, this statement is write here to tells the

compiler to include the declarations of all standard input, output library functions which are

stored inside the header file stdio.h. We will learn more about header file in the other post.

#2: int main()

 main is a pre-declared functions in the C language which is defined by the programmer

 while writing a program, to run or execute the program.The main function is declared in the

 C language but we can define in our way. The main function is necessary to execute or run

 the program, without main function we cannot execute our program. The main function is

 starting point to the start executing our program. We will learn more about function and their declaration in the others post.

#3: printf(“Hello World!”);

“Hello World!” is sequence of the characters that are called string in the C programming

 language that are pass to the printf function to display text "Hello World!" on the console

 output screen(monitor). printf is a library function that is responsible to display text on the 

 standard output device in the C programming language. printf function is declared in header

 file stdio.h. Will will learn more about input and output related function in the other post.

#4: { }

 These symbols are used to create blocks of function, if ,if-else, looping, switch, structure ,union others statements in the C programming language. The block are collection of codes 

 or statements to a particular function and others statements.

 #5: return 0;

 return (0);this statement is returning the control of this program to the calling function or

 system that is our operating system because main function is called by the operating   system in the C programming language. We will learn more about calling function in the

  others post. with value 0 return value 0 represent that’s program’s execution complete

  successfully.