1
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Now instead of an interface you can also add the read only modifier.

2
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You can not add public or private or anything like that.

3
00:00:10,790 --> 00:00:17,690
This is not possible on an interface but you can at read only to make it clear that this property in

4
00:00:17,720 --> 00:00:24,260
whatever object you built based on this interface must only be set once and is read only thereafter

5
00:00:24,290 --> 00:00:26,400
so that it can't be changed off.

6
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Do you object has been initialized.

7
00:00:28,490 --> 00:00:36,210
This is also something if we use a type instead which you can use on a type if you want to though.

8
00:00:36,230 --> 00:00:41,960
So again these two things are very similar here but it's more common or seen more often that if you

9
00:00:41,960 --> 00:00:47,450
will really want to work with an object you use an interface for that and read only just one other thing

10
00:00:47,450 --> 00:00:54,020
you can add there as an extra feature you can set up with read only added here by the way you see I

11
00:00:54,020 --> 00:01:01,110
didn't added here in the class I didn't add read only here and still if I now go to User 1 and I try

12
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to set name to something else I get an error here already because it's read only.

13
00:01:06,230 --> 00:01:11,960
And of course I also get that if I save it and it tries to compile that so the interface is really having

14
00:01:11,960 --> 00:01:17,570
an effect here once we implemented into our class even though I didn't add read only here the class

15
00:01:17,570 --> 00:01:23,900
knows that it implements readable and it automatically assume state the property name which we have

16
00:01:23,900 --> 00:01:29,600
here which we need to have because of the interface is read only because that is what we set up inside

17
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of the interface.

18
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And that's of course pretty convenient as well.