java - Uno Project: Making sure that a illegal plays return correctly? -

i writing chunk of program play uno other classes. uno project finished, need sure part checks make sure on moves after wild card played, play either legal card or return -1. here code:

import java.util.*; public class alexal_unoplayer implements unoplayer { public int play(list<card> hand, card upcard, color calledcolor, gamestate state) {     int play = -1;     boolean havewild = false;     boolean matcheswildcall = false;     int indexofwild = 0;     //turn number of cards players holding ints later use     int[] array = state.getnumcardsinhandsofupcomingplayers();     int playernext = array[0];     int playertwonext = array[1];     int playerbefore = array[2];     color upcardcolor = upcard.getcolor();      for(int = 0; < hand.size(); i++)     {         //see if have wilds         if(hand.get(i).getrank().equals(rank.wild) || hand.get(i).getrank().equals (rank.wild_d4))         {             havewild = true;             indexofwild = i;         }         //set upcard color calledcolor if wild or wild_d4 played         if (upcard.getrank().equals(rank.wild) || upcard.getrank().equals(rank.wild_d4))         {             upcardcolor = calledcolor;         }         //always play card matching rank of upcard, if possible, or play first in hand matches color         if(hand.get(i).getcolor().equals(upcardcolor))         {             if(hand.get(i).getnumber() == upcard.getnumber())             {                 play = i;             }         }          //if cornered(no matching number or color), play wild         else if(havewild == true)         {             play = indexofwild;         }          //hold reverse cards until person next after me has less cards person before me         if(hand.get(i).getrank().equals(rank.reverse) && playernext < playerbefore)         {             play = i;         }          //play skips when person next me has less cards me         if((hand.get(i).getrank().equals(rank.skip) || hand.get(i).getrank().equals(rank.draw_two)) && playernext < hand.size())         {             play = i;         }      }     return play; }  public color callcolor(list<card> hand) {     //strategy: change color 1 i'm holding of     color changeto = color.green;     int numblues = 0;     int numgreens = 0;     int numreds = 0;     int numyellows = 0;     //find out how many of each color i'm holding     for(int = 0; < hand.size(); i++)     {         if(hand.get(i).getcolor().equals(color.blue))         {             numblues++;         }         else if(hand.get(i).getcolor().equals(color.red))         {             numreds++;         }         else if(hand.get(i).getcolor().equals(color.green))         {             numgreens++;         }         else if(hand.get(i).getcolor().equals(color.yellow))         {             numyellows++;         }     }     //find out i'm holding of , call color     //if no majority, return favorite color(green)     if(numblues > numreds && numblues > numgreens && numblues > numyellows)     {         changeto = color.blue;     }     else if(numreds > numblues && numreds > numgreens && numreds > numyellows)     {         changeto = color.red;     }     else if(numgreens > numblues && numgreens > numyellows && numgreens > numreds)     {         changeto = color.green;     }     else if(numyellows > numblues && numyellows > numgreens && numyellows > numreds)     {         changeto = color.yellow;     }     else      {         changeto = color.green;                 }     return changeto; } } 

for reason, output telling me this:

you given hand:   0. g7   1. g5   2. g+2 , card was: w , called color was: yellow , (wrongly) returned 2. valid plays have included: -1 

can provide insight on why getting error , how fix it? appreciated!

based on code, hard wrong implementation.

did try step-by-step debugging of play function? alternately, beneficial instrument code more trace statements better figure out issue might occurring.

for example:

every play variable gets assigned value, print value console context of in code.

if(hand.get(i).getnumber() == upcard.getnumber()) {     play = i;     system.out.println("number match step: play = " + play ); // can add such line } 

this should give idea when play's value getting mutated 2 unexpectedly.

just clutching @ straws here, expected values of getcolor , getnumber wild cards.

in case have them set green or 2 respectively, might explain output seeing because of following fragment of code.

//always play card matching rank of upcard, if possible, or play first in hand      matches color         if(hand.get(i).getnumber() == upcard.getnumber())         {             play = i;         }         else if(hand.get(i).getcolor() == upcardcolor)         {             play = i;         }