Help with type-casting & dereferencing of void pointers (C)

Question

Could anyone please explain why this code ( for finding the square of a number) needs type-casting & dereferencing :-

https://code.sololearn.com/cSWEUTgA4iTF/?ref=app

But this one doesn't (also for finding the square of a number) :-

https://code.sololearn.com/cSfsRkPR8EdL/?ref=app

Also, do we have to follow the procedure that we used with float for other data types too(long, double, etc.)? Or is the procedure exclusive for float data type?

Answer 1

Can you change your question into C?