Why is the answer correct?

Question

The forth quiz in Data Types, Arrays, Pointers
The second question is,'Which of the following are legal variable names in C++?'
The choices are 'salary' '14var' name3_var' '&*^var'
The answer is 'salary' and 'name3_var'
Even though I know why 'salary' is correct
But I have no idea why 'name3_var' is correct
If 'name3_var' is correct, why isn't '14var' correct

Answer 1

There are certain rules for naming c++ variables.
https://mathbits.com/MathBits/CompSci/DataBasics/naming.htm

Answer 2

You will find that a number of languages don't allow a variable to start with a number.

Answer 3

it's starting with 14var ,it's shouldn't have digits at first It should have case sensitive alphabet then you can go with 0-9 digits and any special symbol so,but it should start with alphabet it's rule !!

Answer 4

An identifier must start with a letter
We can also use digits and underscores (after starting with a letter )

Uppercase and Lowercase are different

☝Read these points

Answer 5

you cant start a variable with a number