## April 19 Assignment

### Instructions

Please log into cs.bridgewater.edu. Navigate to the csci101/hw/apr19 directory in your git repository. Write a program in a file named Practice.java that satisfies the following program specifications. When finished, push your code to GitHub.

### Program Requirements

Write a method named `createMatrix` that takes two integers as arguments and returns a 2D array with a length (number of rows) equal to the value in the first parameter and whose elements (rows) have a length equal to the value in the second parameter.

Write a method named `printMatrix` that takes a 2D array of integers as an argument and prints the contents of the array to the screen with each row printed on a separate line and with spaces between the elements.

Write a method named `computeSum` that takes a 2D array of integers as an argument and returns the sum of all of the elements in the array.  Do not assume that each row has the same number of elements.

In `main` do the following.

• Ask the user for two integers, read them in from the keyboard, and store them in variables named `numRows` and `numCols`.
• Create a 2D array having the dimensions equal to the values in `numRows` and `numCols` by calling `createMatrix`.  Store the reference to the new array in a variable named `matrix1`.
• Print the contents of `matrix1` to the screen using `printMatrix`.
• Compute the sum of the elements in `matrix1` using `computeSum`.  Store the sum in a variable named `sum`.  Print the value in `sum` to the screen.
• Ask the user to enter an integer, read in the value from the keyboard, and store the value in a variable named `newValue`.
• Set all of the elements in `matrix1` that have an even row index (e.g. 0,2,4,…) AND an even column index to the value stored in the variable named `newValue`.
• Print the contents of `matrix1` to the screen using `printMatrix`.

## April 16 Assignment

### Instructions

Please log into cs.bridgewater.edu. Navigate to the csci101/hw/apr16 directory in your git repository. Write, compile, and run the program described in Exam 2.

## April 12 Assignment

### Instructions

Please log into cs.bridgewater.edu. Navigate to the csci101/hw/apr12 directory in your git repository. Write a program in a file named `Practice.java` that satisfies the following program specifications. When finished, push your code to GitHub.

### Program Specification

Write a method named `printMatrix` that takes a 2D array (matrix) of integers as an argument and prints the elements in the matrix to the screen with each row of elements appearing on a separate line.

Write a second method, also named printMatrix that takes a 2D array (matrix) of characters as an argument and prints the elements in the matrix to the screen with each row of elements appearing on a separate line.

In `main()` please do the following.

• Creates a 3 x 3 2D array of characters named `matrix1` with the following values:
c a t
a t e
t e a
• Print the contents of `matrix1` using the `printMatrix` method.
• Create a 3 x 3 2D  array of integers named `matrix2`.  Using nested for-loops initializes the 2D array with following values:
1 1 1
1 1 1
1 1 1
• Print the contents of `matrix2` using the `printMatrix` method.
• Change the element at row 1, column 1 in `matrix2` to the value 7.
• Print the contents of `matrix2` using the `printMatrix` method.
• Write a fragment of code that creates a 3 x 3 2D array of characters named `matrix3` and using nested for-loops populate matrix3 with the values in  `matrix1` (in the same order).
• Print the contents of `matrix3` using the `printMatrix` method.
• Get the value of the element at row 1, column 1 in `matrix3` and store it in a variable named `elm`.  Print the value of elm to the screen.

## April 9 Assignment

### Instructions

Please log into cs.bridgewater.edu. Navigate to the csci101/hw/apr9 directory in your git repository. Write a program in a file named `Practice.java` that satisfies the following program specifications. When finished, push your code to GitHub.

### Program Specification

• Write a method named `initArray` that has two integer parameters named `k` and `v`. The method returns an integer array of size k and initializes all of elements in the array to the value v.
• Write a method named `printArray` that takes an array of integers as an argument and prints the integers to the console, all on a single line, with spaces between them.
• Write a method named `sumArrays` that takes two integer arrays with the same length named `arr1` and `arr2` as arguments and returns a new array named `temp` of the same length. For each index i, `temp[i] = arr1[i] + arr2[i].`
• Write a method named `elementExists` that takes an integer named `k` and array of integers named `arr` as an arguments and returns true if the value stored in k is found in the array named `arr`, and returns false otherwise.
• Write a method named `main` that does the following.
• Declare an array of integers named `arr1` and initialize it to an array of 10 integers, all set to the value 2, using the `initArray` method.
• Print the elements in `arr1` to the console by calling `printArray`.
• Declare an array named `arr2` and initialize it the the values 1 through 10.
• Compute the sum of `arr1` and `arr2` by calling `sumArrays`.  Store the array that is returned by `sumArray` in a variable named `arr3`.
• Print the elements in `arr3` to the console by calling `printArray`.
• Print the the screen true if, using the `elementExists` method, `arr3` contains the value 9. Otherwise print false.
• Print the the screen true if, using the `elementExists` method, `arr3` contains the value 15. Otherwise print false.
• Declare an array named `arr4` and initialize it to an array that can hold 10 integers.
• Use a for-loop to populate `arr4` using data input by the user.
• Print the elements in `arr4` to the console by calling `printArray`.