Identifier is used to name various elements of program such as variables, constants, functions, arrays, functions etc. An identifier is a word consisting of sequence of Letters, Digits or _(underscore).
Rules to Name identifiers are
- The variables must always begin with a letter or underscore as the first
- The following letters can be any number of letters, digits or underscore.
- Maximum length of any identifier is 31 characters for external names or 63 characters for local
- Identifiers are case Ex. Rate and RaTe are two different identifiers.
- The variable name should not be a
- No special symbols are allowed except underscore. Examples:
Sum roll_no _name sum_of_digits avg_of_3_nums
Invalid Identifiers and reason for invalid:
$roll_no - Name doesn‟t begin with either letter or underscore
for - keyword is used as name
sum,1 - special symbol comma is not allowed
3_factorial - name begins with digit as first letter