Scala language learning-08-abstract classes

One 、 Personal understanding

（1） Constants and variables in abstract classes are allowed to be uninitialized , A defined method may not write a method body .

（2） It is not allowed to create instances of abstract classes , Otherwise, it will prompt you to report an error .

（3） Abstract classes do not allow multiple inheritance , That is, a class can only inherit one abstract class .

Two 、 Test code

object TestAbstractClass {
    
    def main(args: Array[String]): Unit = {
    
        val ClassStudent: Student = new Student
        ClassStudent.Eat()
        println(ClassStudent.age)
        println(ClassStudent.name)
    }
}

abstract class Person{
    
    // Abstract properties can be uninitialized 
    val name: String
    var age: Int
    
    // Abstract methods may not define method bodies 
    def Eat(): Unit
}

// Abstract class inheritance 
class Student extends Person{
    
    override val name: String = "Czg"
    override var age = 12
    
    override def Eat(): Unit = {
    
        println("Student Eat !!!")
    }
}

3、 ... and 、 test result

Student Eat !!!
12
Czg