C Tokens and Identifiers

What is identifiers, tokens and variables.Every C word is classified as either keyword or identifier. All keywords have fixed meaning and these meanings cannot be changed.Keywords serve as basic building blocks for program statements.

C Identifiers & Tokens

Idnetifer refers to the name of variables,functions and arrays.These are user-defined names and cionsist of a sequence of letters and digits, with a letter as a first character.Both Uppercase and lowercase letters are permitted, although lowercase letters are commonly used. The underscore character is also permitted in identifiers.

C Tokens Chart

• In c programming individual words characters etc are called as tokens.
• Tokens are building blocks of C programming.

Token Example

SNO	Token Type	Example 1	Example 2
1	keyword	do	while
2	Constants	number	sum
3	Identifier	-77	89
4	String	"aaa"	"soft"
5	Special symbols	@	*
6	Operators	++	/

Basic Building Blocks and Definition:

Token	Meaning
Keyword	A variable is a meaningful name of data storage location in computer memory. When using a variable you refer to memory address of computer
Constants	Constants are expressions with fixed value
Identifier	The Identifier is usually used for variable names
String	Sequence of characters
Special symbol	Symbols other than the alphabets Digits and white spaces
Operators	A symbol that represent a specific mathematical or non mathematical action

Keywords in c programming language

1. keywords are those words whose meaning is already defined by compiler
2. Cannot be used as a variable name
3. There are 32 keywords in C
4. C keywords are also called as Reserved Keywords.

32 keywords in C programming

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