Java implements simple four arithmetic operations (2+3×5+4×6)

Java implements simple four arithmetic operations (2+3×5+4×6)

Realization: The arithmetic number is written in the main function without keyboard typing, and the result is obtained after running.

Mainly pay attention to the following points:

1. Do not use return in the constructor, and use return in the constructor to return an int value, which does not match the Mul type of the created object.
2. A class can have multiple construction methods , and two construction methods with the same name are used in the Add class.

Sequence diagram :

The specific code is as follows:

public class M {
    
    
public static void main(String[] args) {
    
    
	Mul o1=new Mul(3,5);
	Mul o2=new Mul(6,4);
	Add o3=new Add(2,o1);
	Add o4=new Add(o3,o2);
	System.out.println(o4.getValue());
	}
}
class Mul{
    
    
	int a;
	int b;
	public Mul(int a, int b) {
    
    
		// TODO Auto-generated constructor stub
		this.a=a;
		this.b=b;
		getValue();
		}

	public int getValue() {
    
    
		// TODO Auto-generated method stub
		return a*b;
	}
}
class Add{
    
    
	Add i; Mul j;
	int a; Mul b;
	public Add(int a, Mul b) {
    
    
		// TODO Auto-generated constructor stub
		this.a=a;
		this.b=b;
		getValue1();
	}
	
	int getValue1() {
    
    
		// TODO Auto-generated method stub
		return a+b.getValue();
	}
	
	public Add(Add i, Mul j) {
    
    
		// TODO Auto-generated constructor stub
		this.i=i;
		this.j=j;
		getValue();
	}
	int getValue() {
    
    
		// TODO Auto-generated method stub
		return i.getValue1()+j.getValue();
	}
	
}