increment - Java Incremental operator query (++i and i++) -

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i have following code:

public class book {     private static int sample1(int i) {         return i++;     }     private static int sample2(int j) {         return ++j;     }      public static void main(string[] arguments){          int = 0;         int j = 0;         system.out.println(sample1(i++)); //0         system.out.println(sample1(++i)); //1         system.out.println(sample2(j++));//1         system.out.println(sample2(++j));//2         system.out.println(i);//2         system.out.println(j);//2     } } 

my expected output in comments. actual output below:

0 2 1 3 2 2 

i'm getting confused function calls , incemental operator. can kindly explain actual result?

first of need know difference between x++ , ++x;

in case of x++ :

first current value used , incremented next. means present value of x operation , if use x next time incremented value;

in case of ++x :

first current value incremented , used (the incremented value) next, means incremented value @ operation , other after operation.

now lets split code , discuss them separately

method: sample1() :

private static int sample1(int i) {     return i++; } 

this method take int , return first , try increment after returning variable i go out of scope never incremented @ all. exp in: 10-> out 10

method: sample2() :

private static int sample2(int j) {     return ++j; } 

this method take int , increment first , return it. exp in: 10-> out 11

in both case variables change locally, means if call main method variables of main method remain unaffected change (as sample1() , sample2() making copy of variables)

now code of main method

system.out.println(sample1(i++)); // it's giving sample1() `i=0` making `i=1`                                    //   sample1() return 0 too;  system.out.println(sample1(++i)); // it's making `i=2` , giving sample1() `i=2`                                   // sample1() return 2;  system.out.println(sample2(j++)); // it's giving sample2() `j=0` making `j=1`                                    // sample2() return 1;  system.out.println(sample2(++j)); // it's making `j=2` giving sample2() `j=2`                                     // sample2() return 3;