The Java class library is huge. We will not cover it all today. In fact, the remaining eight classes will focus mostly on the class library. However, I do want to take this opportunity to look briefly at one useful class in the library, java.lang.Math. This is a class which contains static methods for performing many standard mathematical operations like square roots and cosines. You will need it for many of this weeks exercises.

The Math class contains several dozen static methods. Recall that to use a static method from a class, you just prefix its name with the name of the class followed by a period. For instance

double x = Math.sqrt(9.0);

You never need to instantiate the Math class directly. (In fact you can't. The Math() constructor is declared private.)

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Copyright 1997, 1998 Elliotte Rusty Harold
Last Modified February 22, 1998