Why to use set/get methods for private fields?

[Klaty]

I am beginner programmer. I have been learning programming language C++, C sharp and Java. I have read and listen from many programmers that good programming style is to never make fields of an object public. They should always be private and use set/get methods to access them from outside of the boundary of object. Why it is like this?? Only security purpose or something else also to use private specification?

[Praetor]

Don't worry you will soon come through this lesson if you are learning the programming language. But for now i would say, we programmers make fields private and use set/get methods to access them, so that fields created may not lose the benefits of Polymorphism, which you would be knowing how important in OOP. Also make note that Properties can be override in other classes. and variables can not. and properties can also be used in interfaces but fields cannot be used.

[Modifier]

I have also learned OOP(Object Oriented Programming), which you know is the basic for all the programming language. In OOP, one of the chapter/lesson is about this Private Data. This lesson tells that make data/fields private for reliability and create getter/setters to work with private data. Important to know is only define getters for values that people need to know about and setters are often not defined so that immutable objects can be created. Hope so by this information you would be able understand the problem.

[MindSpace]

Firstly would say, the private fields are used for making special protection. Provides special protection, by using a specific set/get function which allows you to keep restriction on what the field can be get/set to. User/programmer-defined messages can also shown by using this get/set methods. In big/big-scale project, you need to make private variables for security and many other programming reasons.

[opaper]

In order to make classes safer and easier to change, is to make fields private. As you would be knowing that constructors and methods in the same class can use the fields variables, but member or methods or constructor from outside the class can only see them. So, if this private fields wants to be used someone outside, we make get/set methods for setting and getting values. This makes your program more powerful and secure.

[Reegan]

You would know that the fields and methods can be declared private, protected, public, or package. This are various access level , and if no access level is specified, the field or method access level is package by default. When we define private field or method then it is accessible only to the class in which it is define. So, in order to access this kind of methods or fields we make get/set methods to set and get value. Mainly private access specifier is used to increase security or to make secure the program.