In C++ Programming which of these identifiers is valid/ not valid, why?

Question

1) ABCD
2) a+2Z
3) R.radius
4) Temp_Celsius

Answer 1

Hi,
As C++ is case sensitive language. Therefore a and A, x and X,p and P are different characters, in other words they are not alike.

1) ABCD --> It is valid. It is not like abcd.
2) a+2Z-->Invalid as it contains + sign
3) R.radius--> is valid if R is a structture variable. if no structure has been defined then it is invalid
4) Temp_Celsius--> It is valid. But temp_celcius or TEMP_CELCIUS are not same as C++ is case sensitive.