How does it calculate?

Question

myarr[0][2]= 42; how? why we write this?

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

0 is the first element in the indexing, so myarr [0] is {1,2,3} which is the first element in the myarr list(array) and myarr[0][2] is 3 in {1,2,3}

myArr[0][2] = 42 sets the 3. element whose value is 3 at first, to 42

So {1,2,3} becomes {1,2,42}, remember [0] is the first elemnt, [1] is second and [2] is third