Turbo C: Variables and User Input

Getting input value

In every program, variables are declared and used for the user inputs. From my previous post, we already know how to declare variables, but those variables are static or cannot be changed when we run our program.


This time, we are going to create a program that will let the user to input the value. This basic program will ask the user to enter a value that will be set to our variables, and then the program will get the sum of two inputs.

Code:

By using the scanf(“%d”, &x) we are able to get the user input. (“%d”, &x) will get an integer value of the input and will be assigned in variable x.

Turbo C : Variable Declaration

Declaring Variables

Variables are used to hold a value. It can be a text or numbers or even both. This is very useful in programming especially when you want to display some text/numbers multiple times.

There are types of variables used to make a program. These will give the variables a classification that the computer will understand.

On this part, we will create a simple mathematical addition. Here is the code.

Looking at the codes, we used int type of variable. It is used because we are using variables to hold numeric values.

x, y and z are the variables that we declared. You can use any alphanumeric characters to declare variables. It can be (A, B, C) , (num1,num2,num3),  or it can be a name of your choice.

The x has a value of 100 and y has 200, but z doesn’t have a value. It’s ok, we can declare a value for z later.

printf("Value of X is = %d \n", x);       //---- %d will call the integer value of x

printf("Value of Y is = %d \n", y);       //---- %d will call the integer value of y

This statement will display a text and a variable.

The backslash followed by letter n “\n” will begin a new line.

z=x+y;

printf("The sum of X and Y is = %d", z);

This line will declare the value of z.  z=x+y , it is clear that the value of z will add  the  value of x and  y. And the last part will print the value of z.

Output:

Turbo C : Hello World

Writing Hello World Program

To write a C program, we need a compiler. You can use compilers like DevC++ and CodeBlocks but Turbo C is indicated in our title, so we are going to use "Turbo C". I prefer using Turbo C because some codes doesn't work with the new compilers. You will see what I mean if you try to use different compilers. If you still don't have turbo c, you can download it here (link).

This is a basic program written in C Language. This program will just print the hello world text. It simply show you the basic structure of a program and the use of printf function.


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

void main()
{
clrscr();
printf("HELLO WORLD");
getch();
}

The first two lines are the libraries. There are lots of libraries
that is used to create a program. It is used to allow the functions
that we use in every program.

clrscr() - it clears all previous text displayed.
Printf("hello world") - a function to display a text. The function
that is most important in every program.
getch() - without this, your program will just flash on your screen.

Output: