Question

Which of the following is not a valid variable name declaration?

(a) float PI = 3.14;

(b) double PI = 3.14;

(c) int PI = 3.14;

(d) #define PI 3.14

The question was asked in an online interview.

Asked question is from Variable Names in section Data Types, Operators and Expressions in C of C

Answer 1

Correct answer is (d) #define PI 3.14

Easiest explanation - #define PI 3.14 is a macro preprocessor, it is a textual substitution.