有关return i++的小问题

package com.lirl.sprc;

public class TestReturn {

int a =100;
public static void main(String[] args){

TestReturn return1 = new TestReturn();
int b = return1.pius();
System.out.println("a:" + return1.a +",b:"+b);

}

public int pius(){

return a++;

}
}

***********输出************************

a:101,b:100