How is the plus operator works in case of calculating integer with object?

Question

guys!

How is the operator + implemented and works in Java internally in case when we add integer with Integer object?

package ru.systemres.ru;

public class Main {
    public static void main(String[] args) {
        Integer iOb = new Integer(10);
        int a = iOb + 5;
        System.out.println(a);

    }
}

Is it overloaded? Can you show me some source code from jvm which works with it? Thanks!

vijayraj34 · Accepted Answer · 2017-03-18 10:16:03Z

2

Autoboxing is the automatic conversion that the Java compiler makes between the primitive types and their corresponding object wrapper classes.

During Unboxing (Object(Integer) --to--> Primitive(int))

Implicitly Integer.intValue() is called to return int value.

Please Refer: https://docs.oracle.com/javase/tutorial/java/data/autoboxing.html

edited Mar 18, 2017 at 10:16

answered Mar 18, 2017 at 10:05

vijayraj34

2,44529 silver badges29 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Павел Иванов Over a year ago

Ok, but how does it work internally step by step? Do we change + operator logic depending of the types on the left and on the right param? Or the Integer object behaves differently depending on the parameter? How does it work?

vijayraj34 Over a year ago

Autoboxing mainly occur in two places one is during assignment and other is during method invocation. In your case the variable is stored in primitive int a. So, the compiler is expecting primitive type here and converts the object to int in order to use it. //Internal Working Integer obj = Integer.valueOf(10); int pri = obj.intValue();

Mureinik · Accepted Answer · 2017-03-18 09:49:46Z

0

iOb isn't just any old object - it's an Integer. When you use it in such a context, it's outboxed to an int, and then the calculation is performed.

answered Mar 18, 2017 at 9:49

Mureinik

316k54 gold badges400 silver badges405 bronze badges

Comments

Vasu · Accepted Answer · 2017-03-18 09:56:49Z

0

Is it overloaded? Can you show me some source code from jvm which works with it?

It is NOT overloaded, rather the Integer iOb object will be unboxed to int first and then added with 5 to the variable a.

I suggest you refer here for Autoboxing and Unboxing in Java.

answered Mar 18, 2017 at 9:56

Vasu

22.6k11 gold badges54 silver badges71 bronze badges

Collectives™ on Stack Overflow

How is the plus operator works in case of calculating integer with object?

3 Answers 3

2 Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

2 Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related