Description

Lab Exercise 6

[Experimental Objective]  Learn how to use static method
 Learn how to use static method from other class  Learn how to use method overloading  Learn how to use two dimensional arrays  Learn to develop and invoke methods with array arguments and return values.

[Exercises]

1. Create a class named MyTriangle that contains two static methods
a) public static double area(double a, double b, double c)
b) public static double perimeter(double a, double b, double c)
to compute area and perimeter of a triangle respectively given three valid sides a, b and c.
And add a static method
/** Return true if the sum of any two sides is greater than the third side.
**/
c) public static boolean isValid(double a, double b, double c)
In the main method of MyTriangle, test the three methods you write.
1) Get a, b and c from the Console
2) If a is -1, exit your program and print “Bye~”
3) If a is not -1, use isValid to check the input
4) If the input is valid, compute the area and perimeter and print them
5) If the input is not valid, return false and print “The input is invalid.” 6) Go to 1)

Tips: To call a method in the same class, you can try method_name( ).

Sample:

2. In the MyTriangle class created in Exercise 1, add two another static overloaded methods
a) public static double area(double bottom, double height)
b) public static double area(double a, double b, int angleOfAandB)
to compute the area.
The a) method is to compute area by bottom and height:
area = 1/2 * bottom * height
And the b) method is to compute area by two sides a, b and the angle between the two sides(angleOfAandB)
area = 1/2 * a * b * sin(angleOfAandB)

Then create another class Lab6E2 that contains the main method.
In the main method:
1) Read bottom and height from the Console to compute area by calling the corresponding method you created in MyTriangle;
2) Read two sides a, b and angleOfAandB from the Console to compute area by calling the corresponding method you created in MyTriangle.

Tips: To call a static method in another class class_name under the same file directory, you can try class_name.method_name( ).

3. Enter an integer n, please output the nth term of Fibonacci sequence.
(starting from 0, the 0th term is 0)
* Fibonacci sequence: f(n) = f(n-1) + f(n-2)

Sample：

4. Given a chessboard, 1 represents a black grid and 0 represents a white grid. If a grid is white and the top, bottom, left, and right grids of it are black, we call this grid a “bingo” grid. Please write a method:
public static boolean check(int[][] board, int row, int column)
*board is the chessboard, board[row][column] is the target grid to determine whether a grid is a bingo grid. Use this method to calculate how many bingo grids are on the board and output the result.