Java method()++ VS method()+1 -

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• why doesn't post increment operator work on method returns int? 11 answers

i'm trying class.method()++ won't work.

simple example :

person class

public class person {     private int age;      public void age(int value) {         this.age = value;     }     public int age() {         return this.age;     } } 

in main class

following statements error p1.age()++ :

public static void main(string[] args) {      person p1 = new person();      p1.age(p1.age()++); // error } 

but below works fine :

public static void main(string[] args) {          person p1 = new person();          p1.age(p1.age()+1); // works fine     } 

the main question :

why p1.age()++ error p1.age()+1 doesn't ?

p.s :

i know can :

person p1 = new person();     int myage = p1.age();     p1.age(myage++); 

because

x++; 

is short for

x = x + 1; 

and in case be

p1.age() = p1.age() + 1; // error 

and can't have method call on left hand side of assignment.