C Reserved Keywords

Reserved Keywords

In C, there are a set of reserved keywords that have predefined meanings and cannot be used as identifiers (such as variable names, function names, etc.) because they are part of the language's syntax. These keywords are reserved for specific purposes in the language.

• auto
• break
• case
• char
• const
• continue
• default
• do
• double
• else
• enum
• extern
• float
• for
• goto
• if
• int
• long
• register
• return
• short
• signed
• sizeof
• static
• struct
• switch
• typedef
• union
• unsigned
• void
• volatile
• while

auto	break	case	char	const
continue	default	do	double	else
enum	extern	float	for	goto
if	int	long	register	return
short	signed	sizeof	static	struct
switch	typedef	union	unsigned	void
volatile	while

These keywords (Total 32 keywords) are an integral part of the C language and are used to define control structures, data types, and other elements in your C programs. When writing C code, you should avoid using these keywords as variable or function names to prevent conflicts and ensure your code is syntactically correct.

Escape Sequences

Escape sequences in C are special sequences of characters that are interpreted by the compiler or runtime environment to perform certain actions, such as inserting special characters or controlling the behavior of output. Escape sequences always begin with a backslash '\'.

Here are some common escape sequences in C:

Character Constant	Meaning
\n	Move to new line
\r	Move to new line
\t	Horizontal tab
\v	Vertical tab
\a	Alert (Bell)
\\	Print back slash
\?	Print qustion mark
\'	print singel quote
\"	print double quote
\0	Null character
\?	Question Mark
\nnn	Octal value
\xhh	Hexadecimal Representation

Usage of escape sequences in C:

#include ＜stdio.h＞

int main() {
    printf("Hello\tworld!\n");
    printf("This is a backslash: \\ \n");
    printf("She said, \"Hello!\"\n");
    printf("This is a bell: \a\n");
    printf("This is a hexadecimal representation: \x41\n");
    return 0;
}

Hello   world!
This is a backslash: \
She said, "Hello!"
This is a bell: 
This is a hexadecimal representation: A

Note: Escape sequences are especially useful when you need to include special characters in strings or control the formatting of output.