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This article mainly introduces "how to use classes in Scala". In daily operation, I believe many people have doubts about how to use classes in Scala. The editor consulted all kinds of materials and sorted out simple and easy-to-use operation methods. I hope it will be helpful for you to answer the doubts about "how to use classes in Scala". Next, please follow the editor to study!

To facilitate the writing of subsequent representatives, we create a new code workspace:

Create a Person class:

The "_" is PlaceHolder, so let's take a look at how to use this class:

Here's a look at the use of private [this]:

Therefore, the content defined using privatethis cannot be used externally, which plays a very good protective role.

Next, let's take a look at the class constructor. First, let's look at the use of the main constructor:

You can find that the main constructor of a class in Scala has the following characteristics:

1. The main constructor follows the class name directly, and the parameters in the main constructor are compiled into the fields of the class.

2, when the main constructor executes, it executes all statements in the class that are not included in the method body

Next, let's remove the val in front of name in the main constructor and run it:

You can see that there is an error running at this time, which illustrates the third very important feature of the main build function of the Scala language.

3. If the variable is not declared with val or var in the parameters of the main constructor function, then the variable is at the private [this] level and can only be accessed within the class

Next, let's look at the following subsidiary constructors:

1, the accessory constructor is declared with this

2, the main constructor or other accessory constructor must be called in the accessory constructor

2, inheritance in hands-on Scala

Let's take a look at an example of Class inheritance:

Let's take a look at the method of overriding the parent class using override:

Next, take a look at the overwrite of the field:

At this point, the study of "how to use classes in Scala" is over. I hope to be able to solve your doubts. The collocation of theory and practice can better help you learn, go and try it! If you want to continue to learn more related knowledge, please continue to follow the website, the editor will continue to work hard to bring you more practical articles!

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