Identifiers and keywords

Identifiers and keywords

  • Identifiers are name given to various elements of program such as variables, functions, structures, unions,etc.
  • Identifiers have same rules to construct as the rules for constructing variables names.
  • Uppercase and lowercase letters can be used but have different meaning.
  • eg. sum and SUM have same name but different meaning.
  • INVALID Identifiers: basic-pay, d.a, h-t-a.

Keywords : Keywords are the reserved words that have standard, predefined meaning in c.
We should not have to use keywords to construct variable names .

Keywords in C:

auto, default, break, do, case, char, const,

continue, double, else, enum, extern, float,

for, goto, if, innto, long, register, return,

short, signed, sizeof, static, struct, switch,

typedef, union, unsigned,

void, volatile, while.

NOTE: Keywords are always written in lowercase.