Character Sets in C Programming | CoderGuy

Hi friends, in this article, I tell about some important points that are used in C language.

The Characters Sets.

C has the following set of characters to use in the C program.  These are characters in C language are grouped into the following categories:

a) Letters: A to Z and a to z

b) Digits: 0 to 9

c)Special Symbols. 

Symbols	Name of the symbol
,	Comma
;	Semi colon
“	Quotation mark
:	Colon
‘	Single quotation mark (right pointed)
’	Single quotation mark (left pointed)
?	Question mark
!	Exclamation mark
(,)	Parentheses
|	Pipe
[,]	Bracket
{,}	Braces
/	Slash
\	Back slash
#	Hash
@	At the rate of
~	Tilde
%	Percent
^	Carat
&	Ampersand
+	Plus
-	Minus
*	Asterisk
_	Underscore
<	Less than
>	Greater than
.	Decimal
=	Equal to
$	Dollar
\0	Null Character

White Spaces: Blank spaces, horizontal tab, Carriage retain, new line, backspace and form feed   audible sound (\a).

C tokens:

the basic and the smallest units of the program are called C tokens. There are 6 types of tokens in the C language.

1)keywords.

2)identifiers.

3)constants.

4)strings.

5)operators.

6)Special Symbols.

1)keywords: keywords are the sequence of characters (word) whose meaning has already been explained to the C compiler. Keywords can’t be used as variable names. The keywords are also called reserved words. These

keywords can be used only for specified purposes. They can’t be used as programmer-defined identifiers. The keywords are written in lowercase. the 32 keywords which are the following:

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

2) Identifiers: Identifiers refer to the name of variable, functions, arrays, structures, symbolic constants, etc. these are user-defined names and consist of a sequence of letters and digits with a letter as the first character. Both uppercase and lowercase letters are allowed but both are considered of a different type. Most of the identifiers and conventionally declared in lowercase. Underscore character may also be used and it can be placed in the first position also. identifiers may be of any reasonable length generally of 8 to 10 characters. Certain compilers allow longer names up to 63 characters in ASCII. Two identifiers will be considered to be different if they differ up to 31 characters.

3) Constant: A constant is a quantity that doesn’t change during the execution of the program. Constants are divided into two major categories:

a) Primary Constants: Integers, Character, float/real.

b) Secondary constants: Array, pointer, Structure, Union, etc.

4) Strings: A string is the data type used in programming, such as an integer and floating-point unit, but is used to represent text rather than numbers. it is comprised of a set of characters that can also contain spaces and numbers.

5) Operators: Operators are special characters which instruct that compiler to perform certain mathematical or logical operations on some operands. In a instruction of C program. Operations are specified by operators while operands can be constants, variables or expressions.