Static in Java Tutorial #75
Вставка
- Опубліковано 14 лис 2024
- $1,000 OFF ANY Springboard Tech Bootcamps with my code ALEXLEE. See if you qualify for the JOB GUARANTEE! 👉 bit.ly/3HX970h
The static keyword in java lets you use global variables without creating the object. Learn how to use static easily in this video.
Learn java in just 13 minutes: • Learn Java in 14 Minut...
The java static keyword can be tricky at first... But SURELY you'll get it :) If you followed along, congrats! You learned by-doing!
I hope you enjoyed this tutorial about the static keyword in java! I like to have a nice mix of java tutorials and actual projects for you all :)
Was this able to help you learn static in java? -
Full Java Tutorial For Beginners Playlist: • Full Java Course by Al...
Free Tips: bit.ly/3U6HXcb
Disclosure: The Springboard link provided is linked to my affiliate account & supports the channel.
~
Alex Lee
If you’re new to programming but want a career in tech, I HIGHLY RECOMMEND applying to one of Springboard’s online coding bootcamps (use code ALEXLEE for $1,000 off): bit.ly/3HX970h
add me please
You’re literally the best tutorial person. You don’t assume that people know things, you explain even the basic things and i love that. Thanks so much!
Claymore4Breakfast not to mention, he is really well spoken. Never confusing and never used fillers
Totally agree! I'm going through a java programming class right now, and since the books we use are like "Hey! you already know everything about Java? Then read me!" I just simply read the tasks, then go to Alex channel to accually understand what the heck i'm supposed to do
@@andreassjo7268 I am doing the same thing, I'm doing a video game course and the guy said that it's better to learn the bulk of programming first then to start working on an engine. But he explains so quickly and sometimes he just comes with a new thing and says: Just copy it, like no man, I wanna know what it means so it can be in my head forever.
Yeah, he even explains the origins of "static" and the other alternative to static. Truly an amazing person.
I agree, this guy is awesome
well "static" makes sense, because it does mean standing still: its in a fixed position in memory and its impossible for it to be instanced like with non static fields
What do you mean by instanced?
@@hyphen8d725 to be used, so like lets say you have a class and you instanced it, that meant you did the usual Class a = new Class();
@@hyphen8d725 instance means it’s well... an instance of maybe a method, or variable. It can change based on the new object you created. We could have a static variable that all car objects have 4 wheels. An instance variable could be the color or model of the car.
It means ! Let's say you have a class :
class Car {
static int a=0;. }
So if you create 2 object of this class :
Car c1 = new Car();
Car c1 = new Car();
The two object have a variable a = 3 right ?!!;
Let's do this : c1.a= 1; // that's mean the variable a in the object 1 changed to value 3 ! Yes ! But since we put static keyword to the variable a another thing happen !
all variable a changed to value 3 ! So if we do this :
System.out.println (c2.a)// we will see : 3
And also if we create a new object ;
Car c3 = new Car()
c3.a // by default equal 3!
That's mean not only the variable on object 1 changed!!! But the variable in the class changed also and that's what really mean static keyword
I hope you all understand
@@ahmedtlm9488 "The two object have a variable a = 3 right ?!!;" u maybe wanted to say a = 0, cuz a was intialised with zero here "static int a=0;"
I'm so happy I found this channel, now I can binge and feel like I'm learning something XD
How are these tutorials so good? I’ve watched so many Java/Coding tutorials, none have conveyed concepts as clearly and effectively as you
Yes... Don't quit bro. Usually I don't comment in tutorials but your tutorials did make me comment. Because your way of teaching is simply and straight to the point. Keep up the Good wok.
Awesome tutorial with great explanation, this is definitely a confusing concept and you make it easier to understand! BTW, static or "stand still" does make sense...the static variable can be used to refer to the common property of all objects (i.e. not unique for each object). For example, the college name of every student for a particular college. Suppose there are 100 students in my college, now all instance data members will get memory each time when the object is created. All students have its unique name, studentID, SSN, etc, so there is an instance variable for each student object. But, "college" refers to the common property of all objects. If we make it static, this field will get the memory only once. Since the static variable gets memory only once in the class area at the time of class loading, it has the advantage to make your program memory efficient (i.e., it saves memory).
Thanks for that...keep the fire burning! 🛸
Yes. This. This video would be good to be extended a bit to explain this. Static is used in classes when using inheritance too. Say you have a 'car' superclass and then classes of specific cars as subclasses. Well, (yes I know this wouldn't be necessary in reality) each car has 4 wheels so you could have a 'static int wheels = 4;' in the car superclass. It would be, as explained above, called one time into memory when the superclass is called and then each class for individual cars would be able to reference that without calling it EVERY time one of their individual car objects is called. That is nice for memory. Also, saves a little code.
Hopefully that helped expand this idea.
+++ if you want to count the number of object created for that class having static variable , you can increment that static count =0 value each time you create an object and those changes will be reflected for every object you'll create ,
so let's say static count=0;
but you created 1st object and it got incremented it by 1(by using a function) that is now count=1;
so next time when you'll create 2nd object the count will become 2;
So this variable occupies single space in the memory and it is shared among every object of that class,
so changes made by one object will be reflected back for every object.
Why would anyone dislike your videos... your channel is amazing keep doing what you’re doing
yeah I agree
I'm taking a java class right now and i ALWAYS go to your channel after every lecture to have it reexplained by you. You make it so much easier to understand!
You deserve the views. You don't assume we know anything and that's what people need. I've learned more from you in 1 week of videos than a full semester at college.
Man, you can't even imagine how helpful your tutorials are! You saved a lot of headaches for me!
I love this guy so much, he literally explains even the simplest of things and that too it's easy to understand whatever that he's explaining... My favorite content from Alex is the Nested For Loop explanation... Subscribed immediately... The best tutor I've ever seen on UA-cam till date.
You are the best instructor I've ever seen so far on YT. Thank you Alex for your videos. Keep it up
Another great tutorial. I am at Florida Tech and I am a noob. They say they are structured to help all levels, but they are used to people from all over the world that have been doing this stuff for years. Your basic explanations really help! Thank you!
Static as in the same value wherever it's used. The static keyword essentially tells the program that the object, variable, or method doesn't need an instance of it's parent class to be accessed.
I think it's called static because it's place in the memory doesn't change or something like that, not sure. Nice video BTW!
Oh right!!
Static means that any class can access it. Normal variables will be different for different instances, and static variables will be the same for the same runtime. If you want a variable that does’t change put ‘final’ before it.
@@zachm4389 static has nothing to with who can access the variable. If you do "private static int a", only it's own class can use it.
@̇ bruh
As pretty much explained in the "Thinking in Java (4th edition)" book :)
Static only exist when/while the program runs.
Came here to touch upon what I know already, but I can honestly say this is the best tutoring channel that I've come across!
This channel is a hidden gem I regret not searching deeply since beginning of studying java
you are absolutely the best man, you're like my spirit animal, everyone you say and the way you describe things is detailed enough to where it's easy to understand and I can grasp the general concept and expand on it in my assignments/reading if i decide to read lmao.
The intro of your video explained the entire first year on CS.... So thank you SO much for the vid!!
I just started learning java online. Just found your videos. Learning so much. Thanks
i loved how you say on the beginning of the video exactly what a was expecting to learn while whatching. No other video gave the importance to why/when use the 'static' Keyword. Excelent video and teaching.
When instantiating an object you make a copy of only the non-static methods and attributes of that class but, the static part "attributes/methods/other" is excluded from the instantiated objects and remains unique to the class itself "only one reference exists". This makes it a great way to store metadata about your class and its instances. So normal variables are copied each time you instantiate a new object but static variables are only created once at the class declaration hence the keyword static. Also thanks for bringing this up this helped me dusting off some cobwebs somewhere in my brain :).
Im about to cry over here... the extra three steps you speak of have haunted my life for the past 3 years. Thank you so much for clearing that up!!! You got a thumbs up and sub from me bud!
Subscribed not only because you’re incredible at explaining things, but you seem like a wonderful person, continue doing what you love.
Thanks for the precise explanation with pratical example. Have searched elsewhere for a long time for a a clear explanation regarding for what static is for, but to no avail. Feel fortunate to have found you.
Thanks literally the best explanation i have saw do far..helped a lot !!!!!!
Same! Through my advanced algorithms class, I literally had no idea when to or not to put the static keyword, but I fumbled around so much with it until I finished my work without knowing exactly what the hell static was meant to do!
Thank you again for your great videos, Alex! As far as I know, you can change a static variable. Like if you have a method in your class, and also a static variable a=0, you can, for example, make a++ in your method and your static variable will actually change to 1. If you call again the same method (which increases your a), the method will no longer see a equal to 0 (even tho you had static int a=0), but to 1, so after the method increases your a again, you will actually have a=2; Also, if you have a function, let's say int add(int a){ static int b=10; a=a+b; b++; return a;}. The first time you call the function, it will use b=10; the next time you call the function, it will actually use b=11 (the increased b), even tho at the beginning of the function you say static int b=10; Hope I'm not saying wrong things.
Yes pretty much. Static means it belongs to the class and not to any instance. All instances share it. Only one copy of it exists. So if you changed the value, it would change for all instances.
But you cant define static variables inside a method so your method int add(int a){ static int b=10; a=a+b; b++; return a;} would give an error because you tried to define static int b inside it.
Your videos are short enough for my attention span and you always answer what I came for. Thanks.
i love watching your youtube videos you explain each concept in detail so that can any average student can understand it.
Great vid. I've got confusions from other materials with lots of stuffs that sounds like jargons. Finally realized the term here. Many thanks.
a simple video like this, just clarifies so much, it makes much more sense what i'm doing, ty :)
Just started learning java , I’ve watched all your tutorials already and they have helped so much . I can’t wait to watch and learn more , keep up the great work!
P.S you have a fantastic way of breaking down each step .
This is literally my new favorite channel! You make the absolute BEST tutorials and nothing else compares. Great job!
Finally a simple explanation that works for beginners :) Thank you! I feel like understanding this simple video makes it easier to progress further!
simple and sufficient! thank you for this. Although I'd like to add a point, there's another difference between using the keyword "static" and creating an object to access the variable. When you make a variable "static", and change its value in any method, it changes throughout the entire class. However, when you create an object then access the variable from it and alter its value, it will only change for that specific object, not for the entire class. Hope this helps :)
Thanx!
When I search for something in java and see your video in the results I get relaxed that I will understand it.
Best Java teacher ever~ and u have to go through each video "thoroughly" ~ most online teachers just jump from this point to another quickly without explanation and which cause confusion Alex knows our "confusion"
Aleex, you are so honest, humble person. I like you. This static was not clear for me too. I am soo happy to have you as a teacher. Keep teaching and share your experience.
Your tutorials are great. Its very clear and informative. Im kinda binge watching your tutorials for a couple of days now. Im afraid I might finish watching all your videos within a month.
I hope you make Encapsulation tutorial next.
do not stop making tutorial videos you are the best out of all people online, your channel will boom believe me
Wow, I've been confused about the keyword static for the past 6 months. This finally maked sense! Thank you!
Thanks so much Alex, you helped me clear out some missunderstandings regarding static keyword!
Keep it up, really appreacite what you do
This guy doesn't miss! Most tutorials on UA-cam regurgitate the same things your professor said, but with more examples. It's all computer science theory, lacking practicality. However, Alex answers the questions you type in the search box lol
Hey Alex!
I'm JongUk Park(Brad Park) from South Korea.
First of all, I'm so happy about the fact that I found your channel on UA-cam which is very helpful to me.
I really appreciate you for sharing your amazing video on tutorial for Java beginners like me.
All the best!
Cheers!
You are by far the best tutorial channel that I have found. Now every time I need to learn something I always search for one of your videos. By far, my favorite channel👌🏼
Once again your explanation was way better than the one from my teacher. Thanx
I used to avoid static because like you I thought it means its an unchanging fixed variable aka static, god this makes so much more sense now. Thank you
"I am not gonna stop, anytime soon...", Thank you so much. Keep bringing this content, please.
Static is that part of the code that executes first before any other part of code. Hope this additional bit of info helps too.
"Changes made in an instance variable using one object will not be reflected in other objects as each object has its own copy of the instance variable. In the case of static, changes will be reflected in other objects as static variables are common to all objects of a class."
Source - GeeksforGeeks
i think this is why its called static
Your video’s are amazing. No wonder everybody loves them
This guy is my goat, fr saving me before my exam
i looooovvveee how you explain things its easy to understand for us beginners. but its not to the point that people with experience would be put off. you really have a knack for this.
definitely the best at explaining java !!
Hey man, I usually wont comment for any youtube video but i cant stop myself from commenting to ur video. Im new to java and this error u mentioned above(cannot make static reference to non static field...) has been cracking my head for weeks and was really happy to get a soln from ur video. Keep rocking....
Love how you simplify these OOP concepts in Java. Thank you :)!
you explain all this so well...it finally makes sense!!!!!!!
Awesome explanation. My students really benefit from your videos
Alex you are the best.. Atleast when it comes to java.. Usually I don't comment.. But you deserve one.. Dude
Hard to find quality java content. You rock dude
I am on chapter 8 of the book for a programming class and i just learned this. thanks for the excellent explanation.
thank you so much from my heart ❤
i have finel exam about oop and your videos helps me .as you said the college didn't understand us anything.
@ Alex, you've been a great help with learning Java in a simple and easy to understand way. Thank you. And, you deserve WAY more support! Thanks again.
Thank you for explaining this basic concept with such a simplicity.
Well, I was struggling with this concepts, and I stumbled across a couple of your vids, in this particular one I would recommend checking the video on Static Keyword by Telusko in youtube. This is not spam, I just think it's better explained there.
What I understood from that other video summed up:
-A static variable will have the same value for all the objects in a class(this is why I think static as a name might make more sense)
-Opposite to object variables when you want to change a static variable value, you can call the variable by referencing the class instead of the object. EX:
class Emp{
static String ceo;
}
Emp adrian = new Emp();
Now you can call ceo by:
Emp.ceo = "Adrian";
Instead of:
adrian.ceo = "Adrian"
-The reason why you need to declare it as static it's because main it's also static.
-You can create a "static block" in a class (static {//something}) and will be only called once regardless of how many objects you instantiate.
Yes. And another point is that you dont need to create any objects to use static variabe. In ur example you could access ceo variable even without creation of any objects.
I’m happy with your channel. Please keep continue posting about java 👍🏼
absolutely love your stuff, i really feel like I’m getting a better understanding of the language because of how you explain each individual part of it. Keep up the good work bro
it's 2020 and I'm still satisfied, thank u
Just quick note from my side to clarify the topic.
Please note that I am new in Java so I may understand it incorrectly or on the very beginning level, but the following scheme kind of helped me to finally make it clear and hope will help you as well.
Class variables: non-static and static
When you create non-static Class variable it does not actually mean that this one is saved in the memory cell of your program and you can access this cell from the other part of the code.
But it will be saved only once you create an object of the Class, and number of these cells in the memory, which contain your non-static variable, will depend on number of created objects of this class (copies will be made for each object). And when you try to access the non-static variable you should do it through the object because it is actually saved only for each exact object and not for the Class itself.
Static variable makes it easer because when you create it, at the same time you actually save it in the memory for this Class (not object since you may not have an object at this stage). But since it is already saved in the memory you can access it from any part of your code.
If I am wrong (which I pretty much sure and real memory processing may be different:) please correct or comment!
Clean and clear, that's it.
You’re making my java classes WAAAYYY easier! Thank u!
Thank you my man, for carrying us in this vast world of public static void main(String[] args) {}.
You are an incredible teacher! I've watched so many of your videos
Nice Video!
Another way to say it would be;
a static variable can be accessed from the class itself
normal variables can only be accessed from *instances* of that class.
So a static can be accessed even when a class is not instantiated!
Thank you so much! You have no idea how insightful this video is.
Your explanation is much understandable than my Professor. Big Thanks brother!
This is the most nice video about what static is!!! THANKs
Thanks a lot Alex, for everyone the short-cut of System.out.println() is type sysout + hit buttons ctrl+space.
You are more much better than my professor, I really understand how java works from basic into advance 'cause of your help, keep it up
Thank you very much! Really useful! Thx to your tutorials I think I can do pretty good during my uncoming exam.
Love your videos! It's so easy to understand how you explain.
one of the best tutorials i have come across!!! thank you!!!😊😊
You are awsome you clears my doubt in every single video.. so keep doing it
THANKS MAN!!! You explain things so simple.
Thank you alex for your clear and easy to understand java tutorials
your videos really helps me and I really enjoy java now, thank you
Bro, you make everything make so much sense.
Hi You are amazing! keep it up. you explain to me which is one our lecture with 10 examples of my trainer I was not understand him but you made it my day with 6 mint. good job.
Thanks for your videos Alex, I am taking intro to CS II and when I am not understanding something I watch your videos and makes it much easier! I always advice people about your channel! Keep doing this great job!
Hey man , you are doing great.Just don't stop java tutorial.it is very useful for cs graduate students
Thanks. Explanations are simple yet well explained
your videos are brilliant, i realy love them. it helps soooo so much to survive university
Your videos are the best, god send for college students 🙏🏼
Thank you for slowly going through all the topics. Great explanations
thank you Alex really explained good this bastard static, I never was catching the definition of the static but now finally I got it especially when you named it global I was like "now all the pieces of the puzzle came together".
Thankyou for doing these videos. You have helped me understand lots of concepts.
Off course you views will sky rocket, the clarity of this content is amazing please keep them coming,,,,,, you about to get me through my programming module,,,,cant say the same for that prescribed textbook
This man single handily made my life so much easier