## columns and rows [incomplete]

Write the following methods in a Java program:

a) A Java method fillArray() that shall fill a 2D array from the keyboard . The method input parameters are an array A and the array size.
b) A Java method printArray() that shall print the elements of 2D array. The method input parameters are an array A.
c) A Java method multiply_ScalarMatrix() .This method shall print the result of multiplying a 2D array by a number . The method parameters are: array A and the number n.
d) A Java method multiplyMatrix() .This method shall print the result of multiplying a 2D array with another 2D array number . The method parameters are: array A and array B

Hint: To multiply 2 matrices?
Step 1: Make sure that the number of columns in the 1st one equals the number of rows in the 2nd one.
Step 2: Multiply the elements of each row of the first matrix by the elements of each column in the second matrix.
Step 3: Add the products
For details : Matrix Multiplication: How to Multiply Two Matrices Together. 1st you need to ...

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I have done (a) and (b) and didn't know how to do (c) and (d)
that's what i did so far:

```
Scanner read = new Scanner(System.in);

int row = 0;
int col = 0;

System.out.println("insert row");
System.out.println("insert col");

int a[][] = new int[row][col];

fillArray(a, row, col);
printArray(a, row, col);
System.out.println("The sum is: " + sumArray(a));

}
//Fill array

public static void fillArray(int array[][], int a, int b) {
Scanner read = new Scanner(System.in);
for (int i = 0; i < a; i++) {
for (int j = 0; j < b; j++) {
System.out.println("please insert item number [" + i + "][" + j + "]");
}
}
}

public static void printArray(int array[][], int a, int b) {

for (int i=0; i<a; i++) {
for (int j=0; j<b; j++) {
System.out.print(array[i][j]+" ");
}
System.out.println("");
}
}

public static int sumArray(int a[][]) {
int sum = 0;
for (int i = 0; i < a.length; i++) {
for (int j = 0; j < a.length; j++) {
sum = sum + a[i][j];
}
}

return sum;

}
}```