Java – why does the following code compile without errors?

I am new to Java and try to understand the following The length of the array is different The code still executes without any errors I don't understand why If anyone can clarify

public class Practice {
    public static void main(String[] args){

        int [][] a = {{1,2,3},{4,5}};
        a[0] = a[1];
    }
}

Solution

A [0] and [1] are both int arrays (that is, their type is int []), so one can be assigned to another, regardless of the length of the current array they refer to

Your code is not much different from the following code:

int [] a = {1,3};
int [] b = {4,5}
a = b;

Or from this Code:

Object a = ...
Object b = ...
a = b;

In both cases (as in the original code), you are changing the value of the reference type variable to reference other objects