C PROGRAMMS

 

c program examples

C program examples :- These programs illustrate various programming elements, concepts such as using operators, loops, functions, single and double dimensional arrays, performing operations on strings, files, pointers etc. Browse the code from simple c program to complicated ones you are looking for, every one of them is provided with output. C program download with executable files, so that you save on your computer and run programs without compiling the source code. All programs are made using c programming language and Turbo C compiler, most of these will work under Dev c++ compiler also. The first program prints "Hello World" on screen.

C codes

c programming examples

Example 1 - C hello world program
/* A very simple c program printing a string on screen*/

#include
 
main()
{
    printf("Hello World\n");
    return 0;
}

Output of above program:
"Hello World"

 

Example 2 - c program to take input from user using scanf

#include
 
main()
{
   int number;
 
   printf("Enter a number\n");
   scanf("%d",&number);
 
   printf("Number entered by you is %d\n", number);
 
   return 0;
}

Output:
Enter a number
5
Number entered by you is 5

 

Example 3 - using if else control instructions

#include
 
main()
{
   int x = 1;
 
   if ( x == 1 )
      printf("x is equal to one.\n");
   else
      printf("For comparison use == as = is the assignment operator.\n");
 
   return 0;
}

Output:
x is equal to one.

 

Example 4 - loop example

 

#include
 
main()
{
   int value = 1;
 
   while(value<=3)
   {
      printf("Value is %d\n", value);
      value++;
   }
 
   return 0;
}

 

Output:
Value is 1
Value is 2
Value is 3

Example 5 - c program for prime number

#include
 
main()
{
   int n, c;
 
   printf("Enter a number\n");
   scanf("%d", &n);
 
   if ( n == 2 )
      printf("Prime number.\n");
   else
   {
       for ( c = 3 ; c <= n - 1 ; c++ )
       {
           if ( n % c == 0 )
              break;
       }
       if ( c != n )
          printf("Not prime.\n");
       else
          printf("Prime number.\n");
   }
   return 0;
}

 

Example 6 - command line arguments

#include
 
main(int argc, char *argv[])
{
   int c;
 
   printf("Number of command line arguments passed: %d\n", argc);
 
   for ( c = 0 ; c < argc ; c++)
      printf("%d. Command line argument passed is %s\n", c+1, argv[c]);
 
   return 0;
}

Above c program prints the number and all arguments which are passed to it.

 

Example 7 - Array program

#include
 
main() 
{
    int array[100], n, c;
 
    printf("Enter the number of elements in array\n");
    scanf("%d", &n);
 
    printf("Enter %d elements\n", n);
 
    for ( c = 0 ; c < n ; c++ ) 
        scanf("%d", &array[c]);
 
    printf("Array elements entered bu you are:\n");
 
    for ( c = 0 ; c < n ; c++ ) 
        printf("array[%d] = %d\n", c, array[c]);
 
    return 0;
}

 

Example 8 - function program

#include
 
void my_function();
 
main()
{
   printf("Main function.\n");
 
   my_function();
 
   printf("Back in function main.\n");
 
   return 0;
}
 
void my_function()
{
   printf("Welcome to my function. Feel at home.\n");
}

 

Example 9 - Using comments in a program

#include
 
main()
{
   // Single line comment in c source code
 
   printf("Writing comments is very useful.\n");
 
   /*
    * Multiline comment syntax
    * Comments help us to understand code later easily.
    * Will you write comments while developing programs ?
    */
 
   printf("Good luck\n"); 
 
   return 0;
}

 

Example 10 - using structures in c programming

#include
 
struct programming
{
    float constant;
    char *pointer;
};
 
main()
{
   struct programming variable;
   char string[] = "Programming in Software Development.";
 
 
   variable.constant = 1.23;
   variable.pointer = string;
 
   printf("%f\n", variable.constant);
   printf("%s\n", variable.pointer);
 
   return 0;
}

 

Example 11 - c program for fibonacci series

#include
#include
 
main()
{
   int n, first = 0, second = 1, next, c;
 
   printf("Enter the number of terms ");
   scanf("%d",&n);
 
   printf("First %d terms of fibonacci series are :-\n",n);
 
   for ( c = 0 ; c < n ; c++ )
   {
      if ( c <= 1 )
         next = c;
      else
      {
         next = first + second;
         first = second;
         second = next;
      }
      printf("%d\n",next);
   }
 
   getch();
   return 0;
}

 

Example 12 - c graphics programming

#include 
#include
 
main()
{
    int gd = DETECT, gm;
 
    initgraph(&gd, &gm,"C:\\TC\\BGI");
 
    outtextxy(10,20, "Graphics source code example.");
 
    circle(200, 200, 50);
 
    setcolor(BLUE);
 
    line(350, 250, 450, 50);
 
    getch();
    closegraph( );
    return 0;
}

 

For gcc compiler users

If you are using gcc compiler on linux operating system then you need to modify programs. For example consider the following programs which prints first ten natural numbers

 

#include
#include
 
main()
{
    int c;
 
    for ( c = 1 ; c <= 10 ; c++ )
        printf("%d\n", c);
 
    getch();
    return 0;
}

 

Above source code includes a header file and uses function getch, but this file is Borland specific so it works in turbo c compiler but not in gcc. So the code for gcc should be like

 

#include
 
main()
{
    int c;
 
    /* for loop */
 
    for ( c = 1 ; c <= 10 ; c++ )
        printf("%d\n", c);
 
    return 0;
}

 

If using gcc compiler save the code in a file say numbers.c, to compile the program open the terminal and enter command gcc numbers.c, this will compile the program and to execute the program enter command ./a.out .

C program tutorial

A c program consists of functions and declarations or instructions given to the computer to perform a particular task. The process of writing a program involves designing the algorithm, a flowchart may also be drawn and then writing the source code, after developing the program you need to test it and debug it if it doesn't meet the requirement. To make a program you need a text editor and a compiler. You can use any text editor of your choice and a compiler. An IDE or Integrated Development Environment provides a text-editor, compiler, debugger etc. for developing programs.

A c program must have at least one function which is main. A function consists of declaration and statements, a statement is an expression followed by a semicolon, for example a+b, printf("c programming examples") are expressions and a+b; and printf("computer programming"); are statements. To use a variable we must indicate its type whether it's an integer, float , character. C language has many built in data types and we can make our own using structures and unions. Memory can be allocated during compile time or at run time using malloc. C language has many features such as recursion, portability, pointers, dynamic memory allocation due to which it is used for making portable software programs and applications. C standard library offers functions for mathematical operations, character strings and input/output. The process of making programs which is known as coding, requires knowledge of programming language and logic to achieve the desire output. So you should learn c language basics and start making programs. Learning data structures such as stacks, queues, linked lists etc. using c programming provides you a greater understanding as you learn everything in detail. General belief is to go for other high level languages but it's a good idea to learn c before learning c++ or java.