6.18 (Check password) Some websites impose certain rules for passwords. Write a method that
checks whether a string is a valid password. Suppose the password rules are as follows:
■■ A password must have at least ten characters
■■ A password consists of only letters and digits.
■■ A password must contain at least three digits.
Write a program that prompts the user to enter a password and displays Valid Password if the rules are
followed or Invalid Password otherwise.
7.30 (Pattern recognition: consecutive four equal numbers) Write the following method that tests
whether the array has four consecutive numbers with the same value: public static boolean
isConsecutiveFour(int[] values) Write a test program that prompts the user to enter a series of integers
and displays it if the series contains four consecutive numbers with the same value. Your program
should first prompt the user to enter the input size—i.e., the number of values in the series. Here are
sample runs:
8.2 (Average the major diagonal in a matrix) Write a method that averages all the numbers in the
major diagonal in an n * n matrix of double values using the following header: public static double
averageMajorDiagonal(double[][] m) Write a test program that reads a 4-by-4 matrix and displays the
average of all its elements on the major diagonal. Here is a sample run
Arab Academy for Science, Technology & Maritime Transport
College of Computing and Information Technology
Course: Object-Oriented Programming
Lecturer: Dr.Fahima Maghraby, Dr. Emad Elsamahy, Dr. Yasser Omar, Dr. Shereen Ahmed
Teaching Assistant: Eng.Maiada, Eng. Nada, Eng.Hagar, Eng.Alaa
Sheet: Section 2 Methods
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