There are 6 characteristics:
Keywords
Operators
Separators
Constant
Predefined Functions
Syntax
Keywords
Keywords are words that have special meaning to the C compiler.
An identifier can't have the same spelling and case as a C keyword. We can't use keywords for our own purposes.
There are a total of 32 keywords in C which are as follows:
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 |
Operators
Special types of symbols i.e. are used to perform specific task
Types: Binary operator, Unary operator, Ternary operator, etc.
Total 44 operators are present
Separators:
Separate things called as a token
we can separate individual unit -> token
What is Token
Constant
Variable that doesn't change its value throughout the program is known as a constant.
Types:
Alphanumeric constants -> a-z, A-z, 0-9
Numeric constants -> 0-9
Predefined FUnction
all predefined functions are stored in respective header files.
e.g.
stdio.h -> printf(), scanf(), ...
math.h -> sqrt(), ...
Syntax
Syntax is the rules which need to be followed while developing a program
e.g. To declare variable syntax is -
data_type variable_name ;