why this "myArr[0][2]=42;" is used in this program

Question

public class Program {
public static void main(String[] args) {
int[ ][ ] myArr = { {1, 2, 3}, {4}, {5, 6, 7} };
myArr[0][2] = 42;
int x = myArr[1][0];

System.out.println(x);
}
}

Answer 1

They have just assigned a new value to myArr[0][2] in order to show how to assign a value in a specific position. So now the values of first row are 1,2,42 instead of 1,2,3

Answer 2

you replaced myArr[0][2] with 42, that mean 1,2,3 will be 1,2,42
the output is 4, since you declare x as myArr[1][0]

Answer 3

thanks for your answers