Doubt regarding 2D String arrays in java

[Mansukhdeep Thind]

Hi

While trying out some mock tests, I cam across the following question:

public class ID  
{
    public static void main(String... args)
    {
        Object [] object = new String[5][5];
        System.out.println(object.length);
        int counter=0;
        for (Object o : object )
        {
            counter++;
        }
        System.out.println(counter);
    }
}

My question is that how can we say

Object [] object =  new String[5][5]

? When we are declaring and constructing a 2D array, aren't we supposed to put 2 square brackets on both sides?

[Stephan van Hulst]

It's confusing because you're thinking in terms of "2D arrays". Java doesn't have multidimensional arrays. String[][] means array of array of String.

If you assign a String[][] to an Object[], it means that each element of the object array will hold a String[].

[Mansukhdeep Thind]

Thank you Stephen. Yes , you are correct, There are no 2D/3D/ND arrays in java, but only array or array.

[Winston Gutkowski]

Stephan van Hulst wrote:If you assign a String[][] to an Object[], it means that each element of the object array will hold a String[]...

@Mansukhdeep: It's probably worth adding that you should almost never do this in practise.

In fact, the SCJP exam books are full of code that you would never use in real life; and my advice is to forget it as soon as you leave the exam room - you're unlikely to ever need them again, and they'll probably be more of a distraction than a help.

My advice: Write dumb code.

Winston

[Mansukhdeep Thind]

OK Winston. Perhaps it is as important to know what not to do as it is to know what is correct.

[Campbell Ritchie]

Mansukhdeep Thind wrote: . . . There are no 2D/3D/ND arrays in java, but only array or array.

Agree. But shouldn’t it read “array of array”?

[Mansukhdeep Thind]

Aight!! Like Ali G says.. RESPECT main man!!