Simple c program hello world for beginners

Hello, my friends.

How are you all? I hope you all are doing well and have already come up from the struggle of the pandemic situation.

So let’s start our very first simple c program hello World without wasting any time.

Simple C program Hello World

#include <stdio.h>
void main()
{
   printf("Hello, World!");
   return;
}

Output

Hello, World!

Code Explanation

As it is our very first program, let’s discuss every line to understand the program completely.

1. #include <stdio.h> 

• This is a header file.
• It tells the compiler to include this stdio.h file in the program.
• stdio stands for Standard Input Output file.
• Common input-output functions (such as scanf() and printf()) definitions are contained in this.
• # is a pre-processor directive.
• So basically #include<stdio.h> tells the compiler to include a standard header file which contains the function for input and output.

2. void main()

• main() is the function name
• void is the return type of function.
• The execution of the program begins with the main() function.
• We can use any return type with the main() function depending on the type of function we are defining.

3. printf()

• printf() function is used to display the content.
• Content within double quotes appears as it is on the screen.
• If we have to print the value of any variable/function then we just have to write their name. ( We will discuss this in our next example).

4. return

• return or return 0 is the same thing. So please don’t get confused if you see return 0 somewhere.
• As the name indicates, it gives the command to the controller to return from wherever it has been called because the function has been successfully executed.

5 Statement Termination

• In C language, every statement must have to be terminated otherwise the compiler will give an error.
• ‘;‘ indicates the end of the line or line termination.

Simple C program for adding 2 numbers

Before writing this program one should have knowledge about the following basics of C programming topics

• Data Types in C
• Variables, Literals and Constant
• Input-output in C
• Operators

If you don’t have any idea of the topics I mentioned above, please read the article first and come back here.

If you are still reading this then I suppose either you already know about the topics or you read my articles.

So let’s begin.

We can write the code for this program in 2 ways

Method-1 By using static values

#include <stdio.h>
int main() {    

    int a=5, b=3, sum;
    
    sum = a+b;      // adding sum
    
    printf("Sum of the number is %d", sum);
    
    return 0;
}

Output

Sum of the number is 8

Copy the above code and run it here to see the output with different values.

Code Explanation

• printf(“Sum of the number is %d”, sum);
  • Here the content written in double quotes will appear as it is on the screen, but, the %d is a format specifier for integers and indicates the compiler to print the value of the variable/function at that place.

Method-2 By entering the number at the run time of the program

#include <stdio.h>
int main() {    

    int a, b, sum;
    
    printf("Enter first number: ");   // Asking user to enter 1st number
    scanf("%d", &a);     
    
    printf("Enter second number: ");  // Asking user to enter 2nd number
    scanf("%d", &b);

    // calculating sum
    sum = a + b;      
    
    printf("Sum of %d + %d = %d", a, b, sum);
    return 0;
}

Output

Enter first number: 5
Enter second number: 6
Sum of 5 + 6 = 11

Code Explanation

• The user is asked to enter first and second number.
• These two numbers are stored in variables a and b respectively.

printf("Enter first number: ");
scanf("%d", &a);     
    
printf("Enter second number: ");
scanf("%d", &b);

• Using the + operator we have added two numbers and the result is stored in the sum variable.

sum = a + b;

• Finally, the printf() function is used to display the sum of numbers.

printf("%d + %d = %d", number1, number2, sum);

I hope you have learnt how to write a simple c program.

We will meet with some high-level programs related to basic functioning to understand it better.

Till then, enjoy computer programming and don’t forget to comment if you have any below.