CODEWITHSUNDEEP
java
Daniel van der Merwe
Daniel van der Merwe

Reputation: 1970

Difference between using a method in a class to return a value and referencing the exact value itself

Let's say I have a separate GUI class that has a public boolean called "guiWait" and also has a boolean method that returns guiWait.

What's the difference between:

while(gui.guiWait)...

and

while(gui.getGuiWait())...

Upvotes: 1

Views: 101

Answers (4)

jpmc26
jpmc26

Reputation: 29934

The difference is visibility. When you make guiWait public to be used like the first example, outside callers can modify the value. If you use a method and make the variable private, callers cannot modify the guiWait variable (although they can modify the object it references if it's mutable). Furthermore, if you make a habit of using getters and setters, then later on if you need to add logic to the getting or setting process (such as you need to make the value derived from some other new field), you already have the methods and won't break any caller's code by making the variable private. So it's considered "best practice" to always use getters and setters in Java.

Upvotes: 1

Suresh Atta
Suresh Atta

Reputation: 122008

Its the pure concept of Data Encapsulation in JAVA.

A language mechanism for restricting access to some of the object's components.

A language construct that facilitates the bundling of data with the methods (or other functions) operating on that data.

http://www.tutorialspoint.com/java/java_encapsulation.htm

Upvotes: 0

Srikant Sahay
Srikant Sahay

Reputation: 985

The core concept of OOP is encapsulation. The getter and setter methods (eg. your getguiWait() method) are used so that nobody is able to access the internal fields of an object. This way no one else is able to set the internal fields to an inconsistent/abnormal value. By using the "getter" and "setter" methods (and hiding the inner fields by using private), you ensure that anyone willing to set or get a field will have to go through the checks that you have put up. Example Class Cat can have age as its field. In the setter method you would check that the user input value is not negative. If you allow the age field to be public, someone could potentially set it to negative which would make no sense.

Upvotes: 0

a_schimpf
a_schimpf

Reputation: 765

If guiWait is a public boolean, there is no point in having a "getter" method for it. If it were private or protected, then it'd be a different story. The private-getter method is more flexible because you can change the implementation of the "getting" of that variable, and add checks or whatever inside the method. Private getters/setters also make things clearer and establish which things should be seen by other classes and which are only meant to be used inside a single class they are apart of. If you find you do need a getter for a specific member variable (need some kind of verification or checking), which is very common, then it would be inconsistent to do it just for that variable.

Upvotes: 0

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