n++ and n[0]++

[hin1129]

Code: Select all

public class TestClass {     
  public static void main(String args[ ] )     {        
    int i = 1;        
    int[] iArr = {1};        
    incr(i) ;        
    incr(iArr) ;        
    System.out.println( "i = " + i + "  iArr[0] = " + iArr [ 0 ] ) ;     
  }      

  public static void incr(int   n ) { n++ ; }      
  public static void incr(int[ ] n ) { n [0]++ ; } 
}

why the answer is 1 and 2?
why int i is unchanged but int[] iArr is changed?
iArr [0] should have a default value of 0, how did it get to 2?
is there anything to do with the static keyword in the methods?

[admin]

Have you read about how method parameters are passed? Have you read about pass by value / pass by reference concept? Once you go through that, it will be clear to you.
Which book are you following?

[hin1129]

OCFA Java Foundations Exam Fundamentals 1Z0-811: Study guide for Oracle Certified Foundations Associate, Java Certification (Kindle Edition)
which topic/page should i go over for this question and the Static and non-static questions?

[admin]

You may go through section 11.3 "Passing object references and primitive values into methods".