9. What is composition? Why is composition important?

Pp 4.1 design and implement a class called sphere that contains instance data that represents the sphere’s diameter. define the sphere constructor to accept and initialize the diameter and include getter and setter methods for the diameter. include methods that calculate and return the volume and surface area of the sphere (see pp 3.5 for the formulas). include a tostring method that returns a one-line description of the sphere. create a driver class called multisphere, whose main method instantiates and updates several sphere objects.

Select the correct answer. sean is a computer programmer. he has programmed an application for toddlers that plays nursery rhymes. however, a logic error has occurred in the program. which problem is a likely consequence of the error? a. the program crashes every time the user wants to play the nursery rhymes. b. the program crosses its buffer boundaries and overwrites an adjacent program. c. the program plays a different nursery rhyme than the one the user intended to play. d. the program shows different structures in its programming language code. e. the program introduces new viruses every time the user plays a nursery rhyme.

Use a physical stopwatch to record the length of time it takes to run the program. calculate the difference obtained by calls to the method system.currenttimemillis() just before the start of the algorithm and just after the end of the algorithm. calculate the difference obtained by calls to the method system.currenttimemillis() at the start of the program and at the end of the program so that the elapsed time includes the display of the result. use the value returned by the method system.currenttimemillis() just after the end of the algorithm as the elapsed time.