Identifiers:
Identifiers refer to the names of variables, constants, functions and arrays. These are user-defined names is called Identifiers. These identifier are defined against a set of rules.
Rules for an Identifier
i. An Identifier can only have alphanumeric characters( a-z , A-Z , 0-9 ) and underscore( _).
ii. The first character of an identifier can only contain alphabet( a-z , A-Z ) or underscore ( _).
iii. Identifiers are also case sensitive in C. For example name and Name are two different identifier in C.
iv. Keywords are not allowed to be used as Identifiers.
v. No special characters, such as semicolon, period, whitespaces, slash or comma are permitted to be used in or as Identifier.
vi. C‟ compiler recognizes only the first 31 characters of an identifiers.
|
Valid |
Invalid |
|
STDNAME |
Return |
|
SUB |
$stay |
|
TOT_MARKS |
1RECORD |
|
_TEMP |
STD NAME |
|
Y2K |
|