This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
There is an inevitable loss of precision, but any long number can be approximated by a float number, so the conversion still considered to be a "widening" conversion and done automatically (i.e. without explicit cast). The Java Language Specification section 5.1.2 specifies exactly how these widening conversions work. - Peter