It is necessary to declare the variable as "float"?

Question

In python not is necesary so, im cofuse.

Answer 1

Depends on the language... some language demand the type to be declared or else they will not compile/run.. in other languages like python is not needed because it will try to guess the correct type from the value that you assign to the variable at first. Anyway, you have ways to make shure python is storing the value in the variable as a float: i.e. using the decimal point (even when its not needed) when storing a number in a variable, using typecasting (yourVar = float(someValue)), storing the result from a operation that you know it will return a float, Etc.

Answer 2

in c++ of course it is necessary.

Answer 3

If you are working with rational numbers like pi or e or 1/3 or any other yes, you should. If you don't do it, the program will take the integer part (in pi will take the 3, in 1/3 will take 0...).