What happened in this 42 number example in discription

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

42 replaced 3 in the array
Before:
{ {1, 2, 3}, {4}, {5, 6, 7} }
After:
{ {1, 2, 42}, {4}, {5, 6, 7} }
myArr[0][2] means the third element(3) of the first element of myArr ({1, 2, 3}).

Answer 2

Thanks