Program requirements: Matrix class

The private field is a two dimensional array of int values

Since the size is not yet known, this can be set up as follows:

$\backslash$table$[[6,//$field for two dim array$],[7,$private int$[][]$ matrixVals;$]]$

The constructor calls the setMatrixVals$($mVals$)$ setter method to assign the correct information to the private field

The setMatrixVals$($mVals$)$ setter method must make a copy of the parameter

This copy becomes the private field

The getMatrixVals$()$ getter method must return a copy of the field

Program requirements $($continued$)$: Matrix class

The sameSize$($m$2)$ method returns true if the this object and the parameter Matrix object $($i$.$e$.m2)$ have the same number of rows and columns

Else returns false

The transpose$()$ method returns the this object transposed

Therefore, the rows become the columns and the columns become the rows

The scalarMult$($scVal$)$ method returns the Matrix object that is obtained by multiplying all elements of the this object by the scVal $($data type int$)$ value of the parameter

The add$($m$2)$ method returns the Matrix object that results from adding the this object and the parameter Matrix object

The toString$()$ method returns a consistent representation of the two dimensional array $($i$.$e$.$ the private field$)$

Program requirements $($continued$)$: Matrix class

The getMatrixVals$()$ getter method must return a copy of the field

Why is this important?

If the method returns only the name of the array, it is actually returning the address in memory

Therefore, any other method that has access to this address can potentially change the information stored at that address.

Therefore, to protect the security of the data, we must return a copy and not the address

The same concept applies to the setter method, which is why a copy of the parameter array must be made and assigned to the private field

Note that this will necessitate implementing a nested for loop and copying each value in the correct place