ASCII Values – C Program

Problem Question

Write a program to print all the ASCII values and their equivalent characters using a while loop. The ASCII values vary from 0 to 255.

Explanation of Problem

We need to make a program that will simply print the ASCII values from 0-255. What we do to achieve this is pretty simple. Just use int ranging from 0 to 255 and during the use of printf() function, use %c to print the corresponding character value.

Code

#include <stdio.h>
/*ASCII.c*
*@Language: ANSI C*
*@Compiler: GNU GCC*
*@IDE: Code::Blocks 12.11*
*@Author: Toxifier*
*@URL: http://letsplaycoding.blogspot.com/*
*@Date: 15-04-2014**/
int main()
{
  int i = 0;
  printf("\n\nASCII VALUES\n\n");
  while (i <= 255)
  {
    printf("%d: %c", i, i);
    if(i % 5)
      printf("\t");
    else
      printf("\n");
    i++;
  }
  system("pause");
  return 0;
}

Explanation of Code

#include <stdio.h> -> This is the step which occurs before compilation starts. The compiler calls the C Preprocessor to include the STDIO(Standard Input Output) header file into the program, thus letting the use of the standard input/output functions like printf() and scanf() which come from STDIO.H

int main() -> The entry point of the program where the execution starts. This function has to named main. As per the ANSI specification, the return type has to be int. If you use the traditional C, you may use void as the return type. Since the return type is specified as int in my program, I have to use a return statement at the end of my code. So I use return 0 since zero returned from a function, by convention, implies a correct execution of the program. The return values are used to debug the program.

printf() -> This is a standard output function used to print something on the screen. We have to pass a string to this function which will be displayed on user's terminal.

scanf() -> This is the scanf() function which waits for the user to enter certain value using his/her keyboard. We store the user input at the location in memory which is pointed to by the variable whose address is passed to this function.

printf("%d: %c", i, i); -> With %d the number (integer itself) is printed, and %c prints the corresponding ASCII character.

if(i % 5)
printf("\t");
else
printf("\n");
There’s nothing big about this piece of code. I have used this just to format the output. Using this I got 5 characters per line printed.

system("pause") -> This statement is used to pause the program, until user presses a key. This function is not necessary in your program, I use it to see my outputs paused. If you use cmd to run your programs, you might not need this. If you use linux/unix you might not need this. Depending on your compiler, this function may or may not work. Moreover, removing this line of code from this program, doesn't affect the functionality of the program.

Output(s)