A simple piece of C code
#include <stdio.h> int main() { /* my first program in C */ printf("Hello, World! \n"); return 0; }
#include <stdio.h>
The first line of the program is a preprocessor directive which tells a C compiler to include the contents of file stdio.h. Include files contain additional information used by the program file during compilation. Stdio.h file stands for standard input-output header file and contains various prototypes and macros to perform input or output (I/O)
Main Function
The main() function is where program execution begins and is required by every executable C program. Every function must include a pair of braces marking the beginning and end of the function. Within the braces are statements that make up the main body of the program
Program Comments
Any part of a program that starts with /* and ends with */ is called a comment and is ignored by the compiler. Programmers use comments to explain their code but do these not affect the running of the code
Printf Statement
The printf() statement is a library function used to display information on-screen. In the example above, printf outputs the contents of the quotation marks followed by a new line \n.
The Return Statement
All functions in C can return values. The main() function returns a value and in this instance, the value 0 indicates that the program has terminated normally. A nonzero value returned by the return statement tells the operating system that an error has occurred.
Semicolons
In C, the semicolon acts as a statement terminator and indicates to the parser where a statement ends. Several statements can be included on one line as long as each statement is terminated with a semicolon.