Initialisation of array !!

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);
}
}

in the above code myarr is 3 dimensions i.e., { {1, 2, 3}, {4}, {5, 6, 7} } define in that but in initialisation it accept just 2 brackets i.e., (int [][] myarr) instead of 3 !!

why it is so ???

Answer 1

It's 2 dimensional not 3
{{1,2,3} ,{4} , {5,6,7}}

This array represent this matrix👇🏻
1 2 3
4 0 0
5 6 7

3 curly brackets don't mean that this array is 3 dimensional But it tells you this 2 dimensional array have 3 row

3D array is contain two 2D array you can initialized like that:

Int [][][] myArr ={{{1,2},{3,4}},{{5,6},{7,8}}}
**Note the extra curly braces in 3D array

Answer 2

The array myArr is two dimensional. A 3d array looks like this:

int[][][] threeDArray = { { {1, 2, 3}, { 4, 5, 6}, { 7, 8, 9} }, { {10, 11, 12}, {13, 14, 15}, {16, 17, 18} }, { {19, 20, 21}, {22, 23, 24}, {25, 26, 27} } };

Example taken from Stackoverflow, because I'm too lazy to type it all in ^^
https://stackoverflow.com/questions/23630668/java-3d-array-assign-values

Answer 3

Right, 2 dimensions. width & height.
1,2,3
4
5,6,7