Question

 In C language can the first letter of the Identifier be Underscore? ​

Answer 1

Answer:

The first character in an identifier must be a letter or the _ (underscore) character; however, beginning identifiers with an underscore is considered poor programming style. The compiler distinguishes between uppercase and lowercase letters in identifiers.

Answer 2

Answer:

Rules for naming variables:

underscore( _ ). ... After the first initial letter, variable names can also contain letters and numbers. No spaces or special characters, however, are allowed. Uppercase characters are distinct from lowercase characters.