Inherit ExtendsTwo-super&this

package Test;

public class ExtendsTwo {
　　public static void main(String[] args) {
　　　　Son s=new Son();
　　　　s.print();
　　}
}
class Father{
　　int num1=10;
　　int num2=20;
}
class Son extends Father{
　　int num2=30;
　　public void print() {
　　　　System.out.println(this.num1);//10 Because the subclass inherits the things of the parent class, it can be called with this, if the subclass has it, the subclass is called , otherwise call
　　　　System.out.println(num2) of the parent class;//30 Call the nearest one first, which is actually equivalent to this.num2, but omits this
　　　　System.out.println(super.num2);//20
　　}
}