cannot convert int to int[] and operator is undefined for types int[], int []

I am having issues printing out my array as my loops will not print due to it saying cannot convert int to int[]. and my addition and multiplication wont concatenate as it says the operator "+" and "*" are undefined for types int[],int[]

If someone could help me figure out why these issues are happening as I though I had it written correctly. IM not very knowledgeable with arrays so any information would be greatly appreciated

import java.util.*;

public class Matrix {
	
	public static void main (String[] args) {
		System.out.println("Please enter number of rows");
		Scanner sc = new Scanner(System.in);
		int row = sc.nextInt();
		System.out.println("Please enter number of columns");
		int column = sc.nextInt();
		
		int[][] a1 = new int[row][column];
		int[][] a2 = new int[row][column];
		
		for(int r = 0; r < row; r++) {
			for(int c = 0; c < column; c++) {
				System.out.println(String.format("Enter first [%d][%d] integer",r,c));


				a1[r]= sc.nextInt();	//cannot convert int to int[]


			}
		}
		
		for(int r = 0; r < row; r++) {
			for(int c = 0; c < column; c++) {
				System.out.println(String.format("Enter first [%d][%d] integer",r,c));


				a2[r]= sc.nextInt();	cannot convert int to int[]


			}
		}

		System.out.println("First Matrix: ");
		PrintArray(a1);
		System.out.println("First Matrix: ");
		PrintArray(a2);
		
		add(a1,a2);
		multiply(a1,a2);
		
		
		}
	
	public static void add(int[][] a1,int[][] a2) {
		int row = a1.length;
		int column = a1[0].length;
		int[][] add = new int [row][column];
		
		for(int r = 0; r < row; r++) {
			for(int c = 0; c < column; c++) {


				add[r] = (a1[r] + a2[r]); // operator "+" is undefined for types int[],int[]


			}
		}
		System.out.println("Sum of added arrays: "+ add);
	}
	
	public static void multiply(int[][] a1,int[][] a2) {
		int row = a1.length;
		int column = a1[0].length;
		int[][] add = new int [row][column];
		
		for(int r = 0; r < row; r++) {
			for(int c = 0; c < column; c++) {


				add[r] = (a1[r] * a2[r]); // operator "*" is undefined for types int[],int[]


			}
		}
		System.out.println("Sum of added arrays: "+ add);
	}
	
	public static void PrintArray(int[][] matrix) {
		for(int r = 0; r < matrix.length; r++ ) {
			for(int c = 0; c <matrix[0].length; c++) {
				System.out.println(matrix[r] + "\t"	);
			}
			System.out.println();
		}
	}
}

In your example, a1 and a2 are 2 dimensional arrays.

Your for loop iteration is fine, but a1[r] is an int[] and not int.

You are trying to assign an integer value to an array, so you are getting a cannot convert error.

a1[r]= sc.nextInt();

Should be changed to:

a1[r][c] = sc.nextInt(); 

Similarly addition and multiplication are only available for the primitive type or wrappers but not on arrays.

add[r] = (a1[r] + a2[r]);

Has to be changed to:

add[r][c] = (a1[r][c] + a2[r][c]);

And

add[r] = (a1[r] * a2[r]);

Has to be changed to:

add[r][c] = (a1[r][c] * a2[r][c]);

you have to put this code then it works

your code is fine you just forgot to put an array with two dimensions a[r][c]

import java.util.*;
public class Matrix {
public static void main (String[] args) {
System.out.println("Please enter number of rows");
Scanner sc = new Scanner(System.in);
int row = sc.nextInt();
System.out.println("Please enter number of columns");
int column = sc.nextInt();
int[][] a1 = new int[row][column];
int[][] a2 = new int[row][column];
for(int r = 0; r < row; r++) {
for(int c = 0; c < column; c++) {
System.out.println(String.format("Enter first [%d][%d] integer",r,c));
a1[r][c]= sc.nextInt();    // 2 dimensions a1[r] is not fine
}
}
for(int r = 0; r < row; r++) {
for(int c = 0; c < column; c++) {
System.out.println(String.format("Enter first [%d][%d] integer",r,c));
a2[r][c]= sc.nextInt();    // 2 dimensions a2[r] is not fine
}
}
System.out.println("First Matrix: ");
PrintArray(a1);
System.out.println("First Matrix: ");
PrintArray(a2);
add(a1,a2);
multiply(a1,a2);
}
public static void add(int[][] a1,int[][] a2) {
int row = a1.length;
int column = a1[0].length;
int[][] add = new int [row][column];
for(int r = 0; r < row; r++) {
for(int c = 0; c < column; c++) {
add[r][c] = (a1[r][c] + a2[r][c]); // operator "+" is undefined for types int[],int[]
}
}
System.out.println("Sum of added arrays: "+ add);
}
public static void multiply(int[][] a1,int[][] a2) {
int row = a1.length;
int column = a1[0].length;
int[][] add = new int [row][column];
for(int r = 0; r < row; r++) {
for(int c = 0; c < column; c++) {
add[r][c] = (a1[r][c] * a2[r][c]); // operator "*" is undefined for types int[],int[]
}
}
System.out.println("Sum of added arrays: "+ add);
}
public static void PrintArray(int[][] matrix) {
for(int r = 0; r < matrix.length; r++ ) {
for(int c = 0; c <matrix[0].length; c++) {
System.out.println(matrix[r] + "\t" );
}
System.out.println();
}
}
}

your output for 2 row 2 column for example

Please enter number of rows
2
Please enter number of columns
2
Enter first [0][0] integer
12
Enter first [0][1] integer
36
Enter first [1][0] integer
25
Enter first [1][1] integer
23