Question

Since in C\C++\Java –

int 2a ; //invalid suffix "a" on integer constant

Is there nothing wrong with digits in the rest of variant name although it’s valid syntax ?

Like –

int num1 ;
int num_1st ;
int num_2nd ; 

Answer 1

I’ve never heard of anybody (e.g., any coding standards/guidelines) that had a problem with digits in an identifier. Nonetheless, too many of them can indicate that a vector or array might be preferable — even with only two, your num_1st and num_2nd might be better as numbers[2].