java - Unary operator within main and static method -

i have following 2 codes, , in process of knowing how unary operation works within sop, , main method. let me know how values of "i" calculated within main, , when gets within static method.

any detail background operation of things appreciated, need build logic me understand other related codes well.

thanks in advance help.

class r {      static int test( int i)     {          return i--;      }      public static void main (string[] args)     {          int i=0;         system.out.println(test(i++));         system.out.println(i);         = 0;         system.out.println(test(i--));         system.out.println(test(i));     } } 

result:

0 1 0 -1 

second 1 :

class s {      static int test( int i)     {          return ++i;      }      public static void main (string[] args)     {          int i=0;         system.out.println(test(i++));         system.out.println(i);         = 0;         system.out.println(test(i--));         system.out.println(test(i));     } } 

result:

1 1 1 0 

the key understanding programs behavior remember primitive types java uses call value instead of call reference.

thus name i in test function not reference same value referenced name i in main function.

by example

  public static void main (string[] args) {    int i=0;   system.out.println(test(i++)); 

what's happening here is:

• i's value increased i++ 1

• next test method called old value of i, test (0)

• the return vale of test (0) printed stdout.

to determine return value of test (0) take closer @ test method:

  static int test( int i) {     return i--;   } 

what happens here is:

• the value passed in referenced name i decreased i--

• the old value of returned

as value of 0 passed in resulting return value 0, value gets printed by:

system.out.println(test(i++)); 

in main method. next line:

system.out.println(i); 

will print value named i in main stdout. copy of value of i got passed test method old value still unchanged. number 1 printed stdout.

now it's you

having shown example how trace program flow first 2 results of code using same pattern should able explain other results yourself.