C Hello World Example
Before we study basic building blocks of the C programming language, let us look at a bare minimum C program structure so that we can take it as a reference in upcoming chapters.
A C program basically consists of the following parts:
- Preprocessor Commands
- Functions
- Variables
- Statements & Expressions
- Comments
Let us look at a simple code that would print the words “Hello World!”:
#include <stdio.h>
int main()
{
/* my first program in C*/
print("Hellow World!);
return 0;
}
Let us look at various parts of the above program
- The first line of the program #include <stdio.h> is a preprocessor command, which tells a C compiler to include stdio.h file before going to actual compilation.
- The next line int main() is the main function where program execution begins.
- The next line /* my first program in C*/ will be ignored by the compiler and it has been put to add additional comments in the program. So such lines are called comments in the program.
- The next line printf(“Hello World!”) is another function available in C which causes the message “Hello World!” to be displayed on the screen.
- The next line return 0 terminates main() function and returns the value 0.
Compile & Execute C Program
Let’s look at how to save the source code in a file, how to compile and run it. Following are the simple steps:
- Open your C/C++ compiler and add the above-mentioned code.
- Save the file as “Hello World.c”.
- Now Compile and run by clicking F9 (Code::Blocks).
- If there are no errors in your code the compiler will create a window that will display “Hello World!".