Projects

P$-1\mathrm{.}26$ Write a short Java program that takes all the lines input to standard input and

writes them to standard output in reverse order. That is$,$ each line is output in the

correct order, but the ordering of the lines is reversed.

P$-1\mathrm{.}27$ Write a Java program that can simulate a simple calculator, using the Java console

as the exclusive input and output device. That is$,$ each input to the calculator, be

it a number, like $12\mathrm{.}34$ or $1034,$ or an operator, like $+$ or $=,$ can be done on a

separate line. After each such input, you should output to the Java console what

would be displayed on your calculator.

P$-1\mathrm{.}28$ A common punishment for school children is to write out a sentence multiple

times. Write a Java stand$-$alone program that will write out the following sen$-$

tence one hundred times: "I will never spam my friends again." Your program

should number each of the sentences and it should make eight different random$-$

looking typos.

P$-1\mathrm{.}29$ The birthday paradox says that the probability that two people in a room will

have the same birthday is more than half, provided $n,$ the number of people in the

room, is more than $23.$ This property is not really a paradox, but many people

find it surprising. Design a Java program that can test this paradox by a series

of experiments on randomly generated birthdays, which test this paradox for $n=$

$5,10,15,20,$dots,$100.$

P$-1\mathrm{.}30($For those who know Java graphical user interface methods:$)$ Define a Graphi$-$

calTest class that tests the functionality of the CreditCard class from Code Frag$-$

ment $1\mathrm{.}5$ using text fields and buttons.