Hello world Program in C Programming Language
Notes:
Hello world program in C Programming Language
#include <stdio.h>
Hash symbol indicates the "pre-processor statement".
Any statement that begins with # symbol, indicates it is the pre-processor statement.
#include is a pre-processor directive.
Pre-processor directives are going to direct the pre-processor what to do.
The #include directive is going to direct the pre-processor, to located the stdio.h header file in the c library, if it is available then include that file in main.c file.
Pair of angle brackets indicate locate the given header file inside the C library.
stdio stands for standard input output.
Header files in C language are going to .h file extension.
Why we are telling to include stdio.h because printf function is defined inside the stdio.h file; hence we must include the stdio.h file in the beginning of the source code.
There are variety of pre-processor directives available in C programming language.
Ex: #include, #define, #ifndef, #endif, #error etc.
main():
The main is a function.
An identifier followed by pair of parenthesis indicates a function in C programming language. So main is a function.
As the name itself indicating, it is the main function of every C application.
Execution of any C application begins at main function. So it is the beginning point or entry point of any C application execution.
The main function is an essential function for executing any C application. Without the main function no C application can be executable.
Note:
There should be one and only one main function in any C application
The main function should be written in lower case letters.
A function can return a value.
Here int is a return type that indicates the type of value the main function is returning to the OS.
Returning 0 indicates the program has got executed successfully without any errors.
If any errors found then the compiler itself sends 1 to the OS indicating there is any error in the program.
Pair of flower brackets: {}
Pair of flower brackets is used to group one of more statements. The opening flower bracket indicates the beginning of main function and the closing flower bracket indicates the end of main function. The pair of flower brackets indicates the block of code
printf():
The printf function is meant to display some output on to the console. The sequence of characters enclosed in double quotations is called as string in C programming language. Every C programming statement must end with the semicolon. Semicolon is used to separate one C programming statement from another.
