Initializing a boolean array to false

Question

I have this piece of code below. How do I initialize each element = false?

boolean[] seats = new boolean[10]

I saw a similar question. But, the second line didnt make sense to me (Can you explain the 2nd line?).

 Boolean[] array = new Boolean[size];
 Arrays.fill(array, Boolean.FALSE);

"Next Question" No. Don't change the question. [Ask a new one](http://stackoverflow.com/questions/ask). Changing the question invalidates all the existing answers. — Mark Byers, Sep 01 '12 at 16:58
Yes, he wants you to ask a new question (i.e. a whole new thread) — adrian, Aug 02 '17 at 21:20

Mark Byers · Accepted Answer · 2012-09-01T16:49:28.977

61

The default value for the elements in a boolean[] is false. You don't need to do anything.

The reason it's necessary for Boolean[] is because the default value is null.

To initialize to true, use the overload of Arrays.fill that accepts a boolean[].

boolean[] seats = new boolean[10];
Arrays.fill(seats, true);

See it working online: ideone

edited Sep 01 '12 at 16:49

answered Sep 01 '12 at 16:38

Mark Byers

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That's what I thought. Thanks – AppSensei Sep 01 '12 at 16:39
Ok, how do I initialize it to True then? – AppSensei Sep 01 '12 at 16:41
Simple `Arrays.fill(array, Boolean.TRUE);` – Bharat Sinha Sep 01 '12 at 16:42
Ok, my goal is to read an input from the user. If the user enters '1' initialize an elements 1-5 to be true. if '2' is entered initialize element from 5-10 to be true. – AppSensei Sep 01 '12 at 16:52
Sure, sorry about the confusion. I have posted it above. – AppSensei Sep 01 '12 at 16:58

score 4 · Answer 2 · answered Sep 01 '12 at 16:40

A boolean is initialized to false by default. So you need not to do anything specific here. When you create an array of booleans and don't initialize it all the elements will be be false.

how do I initialize it to True then?

Simple Arrays.fill(array, Boolean.TRUE);

Initializing a boolean array to false

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