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Android Build an Interactive Story App (Retired) The Model-View-Controller Pattern Creating the Story

Joannie Huang
Joannie Huang
6,195 Points
Posted by Joannie Huang
Joannie Huang
6,195 Points

About "mPages[0] = new Page();"

Hi Ben, I want to ask about why in the video, you wrote a line: 

mPages[0] = new Page();

Isn't the mPages array have already been created an Page object by the following code?

mPages = new Page[7];

Could you explain a little bit further regarding the difference if there is without creating an object on each item in array? Thanks :)

2 Answers

Jack Middlebrook
Jack Middlebrook
19,746 Points
Jack Middlebrook
Jack Middlebrook
19,746 Points

In the example, the line:

mPages = new Page[7];

creates the array which can hold references to 7 Page objects. It doesn't actually create 7 Page objects but allocates enough memory for 7 Page objects. The Page objects are then created separately with the following: 

mPages[0] = new Page();

Now the first element in the array points to a new Page object that has been created.

Joannie Huang
Joannie Huang
6,195 Points
Joannie Huang
Joannie Huang
6,195 Points

Thanks, Jack! I think I understand what you meant :)

It's clearly enough.

ian sobo
ian sobo
3,851 Points

just jumping in here to say thanks as well. this cleared up my same confusion

Nitin George Cherian
Nitin George Cherian
4,410 Points
Nitin George Cherian
Nitin George Cherian
4,410 Points

Hello Jack,

Thanks for the answer.

For the code,

mPages = new Page[7];

You have given the comment " It doesn't actually create 7 Page objects but allocates enough memory for 7 Page objects." It is true that it does not actually create 7 Page objects. However, it allocates enough memory for 7 Page object references instead of 7 Page objects. Here is answer from stackoverflow.com which explains the same. http://stackoverflow.com/a/10044424/1220250

Please correct me if I am wrong.

John MacDonald
John MacDonald
8,593 Points
John MacDonald
John MacDonald
8,593 Points

just jumping in here to say thanks as well. this cleared up my same confusion