java - Program won't print out the intersection or difference! Any suggestions? -

import java.util.scanner;  public class setpractice {     public static scanner kbd;      public static final int maxsize = 20;      public static void main(string[] args) {         kbd = new scanner(system.in);         int[] seta = new int[maxsize];         int[] setb = new int[maxsize];         int[] intersect = new int[maxsize];         int[] difference = new int[maxsize];         int sizea, sizeb, intersize, diffsize;          system.out.print("how many numbers in 1st set: ");         sizea = kbd.nextint();         while (sizea > maxsize) {             system.out                     .print("error: set size large. re-enter set size: ");             sizea = kbd.nextint();         }         system.out.println("enter list of integers 1st set: ");         getdata(seta, sizea);         sort(seta, sizea);         system.out.println("the ascending order 1st is:");         print(seta, sizea);          system.out.print("how many numbers in 2nd set: ");         sizeb = kbd.nextint();         while (sizeb > maxsize) {             system.out                     .print("error: set size large. re-enter set size: ");             sizeb = kbd.nextint();         }         system.out.println("enter list of integers 2nd set: ");         getdata(setb, sizeb);         sort(setb, sizeb);         system.out.println("the ascending order 2nd set  is:");         print(setb, sizeb);          intersize = intersection(seta, setb, sizea, sizeb, intersect);         system.out.print("the intersection of 2 sets is: ");         (int x = 0; x < intersize; x++) {             system.out.print(intersect[x] + " ");         }          diffsize = difference(seta, sizea, setb, sizeb, intersect);         system.out.print("\n\nthe difference of a-b is: ");         (int x = 0; x < diffsize; x++) {             system.out.print(difference[x] + " ");         }     }      public static void getdata(int[] set, int size) {          (int x = 0; x < size; x++) {             int num = kbd.nextint();             int count = search(set, size, num);             if (count == 0)                 set[x] = num;             else                 x--;         }     }      public static int search(int[] set, int size, int num) {          int count = 0;          (int x = 0; x < size; x++) {             if (num == set[x])                 count++;         }         return count;     }      public static int difference(int[] seta, int sizea, int[] setb, int sizeb,             int[] resultset) {          int y = 0;         (int x = 0; x < sizea; x++) {             int num = seta[x];             int found = search(setb, sizeb, num);             if (found == 0) {                 resultset[y] = num;                 y++;             }         }         return y;     }      public static void sort(int[] nums, int size) {         int temp;         (int = 0; < nums.length - 1; i++) {             (int j = 0; j < nums.length - - 1; j++) {                 if (nums[j] > nums[j + 1]) {                     temp = nums[j];                     nums[j] = nums[j + 1];                     nums[j + 1] = temp;                  }             }         }      }      public static void print(int[] nums, int size) {         (int = 0; < nums.length; i++) {             if (nums[i] != 0) {                 system.out.println(nums[i]);             }         }     }      public static int intersection(int[] seta, int[] setb, int size, int sizeb,             int[] resultset) {         int count = 0;         (int = 0; < seta.length; i++) {             (int j = 0; j < setb.length; j++) {                 if (seta[i] == setb[j]) {                     count++;                     break;                 }             }         }         resultset = new int[count];         count = 0;         (int = 0; < seta.length; i++) {             (int j = 0; j < setb.length; j++) {                 if (seta[i] == setb[j]) {                     resultset[count++] = seta[i];                     break;                 }               }         }         return count;     } } 

the requirements must use methods , loops reach solution. intersection , difference methods must return int part of assignment instructions!

thank in advance!

test input:

how many numbers in 1st set: 3 enter list of integers 1st set:  34 2 56  ascending order 1st is: 2 34 56  how many numbers in 2nd set: 4 enter list of integers 2nd set:  56 2 33 6  ascending order 2nd set  is: 2 6 33 56  intersection of 2 sets is: 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0   difference of a-b is:  

i think found errors:

1. you use set.length (or seta.length or ...) instead of method parameter (size or sizea or ...) multiple times.

   especially in sort method problematic: sorted arrays start 0s. don't recognize this, since ignore 0s in print method. print way print intersection , difference , you'll see error.

2. you pass intersect parameter difference method instead of difference.

3. you create new array in intersection method. replaces local array, not 1 created in main method. (int arrays initialized 0s)