c programing

[anmol6161]

sir,

void main()

{

printf("\\\\\\\\");

getch();

}

output is only \\\\ slash why???????????????

[timo]

Because each "\\" prints one "\". The reason is that you need what I believe is called an escape character, which is a character indicating a "command" rather than a normal letter. By "command", I mean an output that you cannot properly represent in your source code editor. For example, a carriage return is "\n" (go ahead and printf "this\nis\nan\nexample\nwith\nmultiple\nlines" to test it). The problem is that if you want to print the actual escape character on screen you cannot simply write this character, because the language would expect it to indicate a following "command". The solution is to make printing of the escape character a "command", too. So the command for a new line is "\n", and the command for a backslash is "\\".

This is, by the way not unique to C. If you ever use latex (e.g. for mathematical formulas in this forum) you may encounter the same concept, there.

Edited November 13, 2011 by timo

[khaled]

\ in ASCII is used to represent a special character, since C\C++ have ASCII as their default character-encoding

 

We've \n (new line) \r (line break:win) \t (vertical tab) ...

 

And to represent \ in output, it's considered as a special character .. so we write \\ which represent a single \

 

take this example, and check what happens:

 

void main ()
{
       printf ( "hidden\b\b\b\b\b\b" );
}

 

you will see nothing printed, but actually .. the console first print the characters: h, i, d, d, e, n .. then every

special character \b (backspace) removes a single character