Java access modifiers: (public, protected, private) 🔒

Aug 15, 2023

Java access modifiers: (public, protected, private) 🔒

Java access modifiers public protected private

#java #public #private #protected

//
public: visible in all classes in all packages
protected: visible to all classes in the same package or classes in other packages that are a subclass
default: visible to all classes in the same package
private: visible only in the same class
//

Content

0 -> hey what's going on everybody it's your

1.52 -> bro hope you're doing well and in this

3.28 -> video i'm going to teach you guys about

4.799 -> different access modifiers in java so

7.12 -> sit back

7.759 -> relax and enjoy the show

11.679 -> if you find this video helpful please

13.28 -> remember to like

14.799 -> comment and subscribe your support will

17.119 -> help keep this channel running

19.279 -> all right everyone so axis modifiers add

22.32 -> a layer of security to our programs and

24.88 -> there are three

25.84 -> axis modifiers i'm going to cover

27.92 -> besides the default which is none

30 -> they are public protected and

33.12 -> private so to best demonstrate this

35.28 -> we're going to need some packages

37.2 -> this time so within your project folder

40.16 -> we're going to create

41.28 -> two packages i do have a separate video

44.079 -> on packages

45.039 -> somewhere within this playlist so let's

47.12 -> call this first package

48.48 -> package one and all a package is is a

51.28 -> collection of classes

52.96 -> whereas a class is a collection of code

55.84 -> so

56.16 -> we'll call this package one and click

57.92 -> finish we'll create a second package

60.079 -> called

60.48 -> package2 file new package and this will

63.84 -> be

64.879 -> package 2 and click finish

68 -> we're going to create two classes within

70.159 -> each package

71.28 -> so let's click on package 1 then go to

73.76 -> file

74.32 -> new class we will call this class a and

77.52 -> check public static void main

80.88 -> let's create a second class called b

83.2 -> file new class

84.799 -> and this is also going to be within

86.32 -> package one name

88.24 -> is b then within package two we're going

91.6 -> to create a class called

93.04 -> c file new class c

96.96 -> and lastly file new class

100.079 -> make sure that this is within package

101.759 -> two and this is going to be

103.36 -> a sub this is going to be a subclass

106.479 -> of the a class so a sub

110.32 -> extends a in order for us to

113.759 -> inherit everything from the class a from

116.799 -> package one we'll need to include an

118.96 -> import

119.84 -> so import package1.a but i'm just going

122.96 -> to change this to an asterisk to import

124.96 -> everything

125.759 -> so we'll include some imports within

127.84 -> each of these classes

129.039 -> so let's begin with class a we're going

131.68 -> to import everything

133.04 -> from package 2 class b

136.08 -> import everything from package 2 class c

139.28 -> import everything from package one this

141.92 -> time

142.879 -> so with our a sub class we can now

145.92 -> inherit everything from the a class

148.08 -> within package one

149.599 -> so let's begin with axis modifiers and

152 -> we're first going to discuss

153.519 -> the default access modifier so i'm going

156.239 -> to create a string variable within

158.8 -> my c-class let's say that this is a

161.599 -> string variable called

163.519 -> default message

166.56 -> and this will display or hold this is

170.239 -> the default so currently i'm using

173.76 -> no access modifier and i would like to

176.319 -> see

177.12 -> who or which classes can see this

180 -> default message that has

181.599 -> no access modifier the default access

184.159 -> modifier let's head back to

185.68 -> our a class within package one and let's

188.48 -> create an instance of our c class

190.72 -> well i suppose we also could have made

192.72 -> this a static variable but

194.64 -> hey too late so let's create an instance

197.28 -> of the c class

198.239 -> c c equals new c

201.92 -> and i'm going to attempt to print the

205.12 -> default message variable

206.64 -> of the c class so c dot

210.4 -> default message and i'm just going to

212.799 -> copy this

213.84 -> paste it all right but we're going to

215.599 -> have a problem though and this states

217.36 -> that the field

218.159 -> c dot default message is not visible

221.28 -> that's because anything using the

223.04 -> default axis modifier

224.959 -> is only visible to anything within the

227.28 -> same package

228.319 -> so anything within package 2 is going to

230.72 -> be able to access this default message

233.12 -> variable

233.76 -> but anything within a different package

235.68 -> such as our a class

237.28 -> and b class cannot so let's attempt to

239.84 -> do this again but within our a

241.76 -> subclass so i'm going to copy

244.879 -> everything i have here including the

246.4 -> main method and just paste it within

248.799 -> our a subclass so we now actually

252.959 -> have access to our default message

255.439 -> variable within the c class

257.28 -> because these are both within the same

259.519 -> package

260.479 -> all right well for now i'm going to move

262.72 -> this main method

263.759 -> back to our a class within package one

266.8 -> so let's create another variable and

268.639 -> this is going to be a

270.16 -> public variable so let's use the public

273.759 -> modifier public this is going to be a

276 -> string and let's call this

278 -> public message and this will

281.12 -> hold a string of this

284.72 -> is public all right

287.919 -> now i'm going to attempt to access this

290.8 -> variable

291.52 -> public message from the a class which is

294.32 -> in

294.8 -> package one so c dot

298.32 -> and you can see it right here public

300.4 -> message and this will display

302.72 -> this is public that's because anything

305.199 -> that uses

306.08 -> the public keyword is visible to

309.199 -> any package within the project folder so

312 -> even though this is in package two

313.84 -> it's still visible to anything within

315.68 -> package one and a lot of other classes

317.84 -> use this

318.56 -> such as class c this is public a sub is

321.759 -> public

322.8 -> b is public and a is public now check

325.759 -> this out we have created an instance of

327.919 -> our c class within class a but what

330.8 -> would happen

331.44 -> if we removed the public axis modifier

334.4 -> from the class definition of c

336.72 -> well now currently c is using the

339.52 -> default

340.4 -> access modifier so our class c

343.6 -> is only visible to classes within the

346.56 -> same package

347.68 -> as class c if we go back to class a

351.039 -> while now class a can no longer create

353.6 -> an instance of class c

355.28 -> because the visibility of c has changed

358.16 -> class a

358.96 -> is within package 1 and we can no longer

361.36 -> access class c

362.639 -> because class c is only available to

365.28 -> classes within the same

366.8 -> package so let's change the visibility

369.68 -> of c

370.24 -> back to public so that's all what the

372.319 -> public access modifier is

374.24 -> anything that is public is available or

376.479 -> visible to other packages

378.479 -> our next access modifier is the

380.88 -> protected

382.24 -> access modifier so let's create a

384.96 -> protected variable

386.08 -> let's call this string protected message

390.56 -> and let's change the string to this is

393.759 -> protected

395.039 -> here's how the protected axis modifier

397.199 -> works so

398.24 -> something that is protected is

400.479 -> accessible

401.52 -> to a different class in a different

403.759 -> package

404.56 -> as long as that class is a subclass

408.479 -> of whatever class contains this

410.72 -> protected member

411.919 -> so for this example let's copy this line

414.479 -> of our protected message

416.319 -> and paste it within the a class we're

419.28 -> going to take our main method

421.28 -> cut it and then copy this within our a

424.479 -> subclass let's

427.599 -> remove this instance of our c class and

430.4 -> we're going to create an instance of our

432.08 -> a

432.4 -> subclass so a sub let's call this a sub

435.919 -> lower case equals new a sub

441.12 -> so a sub extends a even though a

444.56 -> is in a different package we have access

447.599 -> to this protected variable because

450.16 -> something that is protected

451.84 -> is accessible to a different class in a

454.72 -> different package

455.68 -> as long as that class is a subclass

458.72 -> of whatever class contains that

460.88 -> protected member

462.16 -> so we have an instance of our a subclass

464.96 -> and we should be able to

466.319 -> access this protected message variable

469.759 -> so system.out.printline a

472.96 -> sub dot and here is our protected

477.199 -> message

478.16 -> and it just states this is protected and

480.96 -> our last access modifier

482.72 -> is private so let's create a private

485.039 -> variable

486.08 -> private let's copy what we have for our

488.8 -> default message

489.84 -> and change default to private so this

492.639 -> will be

493.44 -> private message and the string will be

496.16 -> this

497.039 -> is private all right now let's copy all

500.639 -> of this

501.199 -> and paste it within class beep so

504.4 -> something that is private is only

506.72 -> visible to

507.759 -> the class that it contains itself so

510.8 -> only class b has access to this private

513.76 -> message

514.719 -> so i'm going to revert everything that i

517.76 -> changed for class a so let's put this

519.68 -> main method back in

521.2 -> remove the main method from a sub and

524.08 -> let's create an instance of

525.68 -> our b class so b b

528.8 -> equals new b and i would like to

532.64 -> access this private message found within

535.68 -> class b so system.out.printline

539.12 -> b dot but it doesn't appear that we can

542.72 -> actually see that

543.92 -> so let's attempt to actually print this

546.48 -> b dot private message

548.16 -> but this states the field b private

550.24 -> message is not visible

552 -> that's because something that is private

555.04 -> is only visible to the class that it

557.36 -> contains and

558.16 -> nothing else even if it's within the

560.08 -> same package well that's the basics of

562.64 -> access modifiers we have public

564.959 -> protected the default access modifier

567.519 -> and private

568.56 -> so if you would like a copy of all this

570.08 -> code i will post all of this in the

571.839 -> comments down below

573.12 -> but yeah that's the basics of access

575.36 -> modifiers

576.16 -> in java hey you yeah i'm talking to you

580.56 -> if you learn something new then you can

582.56 -> help me help you

584.48 -> in three easy steps by smashing that

586.959 -> like button

587.839 -> drop a comment down below and subscribe

590.32 -> if you'd like to become a fellow bro

606.56 -> [Music]

612.48 -> you

Source: https://www.youtube.com/watch?v=T632kAJ_9VA