java - Receiving " error: ' void ' type not allowed when checking JButton status in Tic Tac Toe game -

i have 9 scenarios making 9 conditional statement see if jbutton have been pressed , no winner found, giving me " error: ' void ' type not allowed here.

import javax.swing.*; import java.awt.*; import java.awt.event.*;  public class tictactoe extends jframe { private final int height = 450; private final int width = 500; private static jbutton [] button = new jbutton[9]; private static action [] playerturn = new action[9]; private static jlabel [] label; private int player = 1; private font arial = new font("arial", font.bold, 20); private static int lockbuttons = 0;   public tictactoe () {     settitle( " tic tak tow ");     setsize( height, width);     setdefaultcloseoperation(jframe.exit_on_close);        setlayout(new gridlayout(4,3));      int num = 0;     for(int = 0; < 9; i++ )     {          button[i] = new jbutton( "b" + + 1);         playerturn[i] = new action();         add(button[i]);         button[i].setfont(arial);         button[i].addactionlistener(playerturn[i]);     }       setvisible(true); }  private class action implements actionlistener {     public void actionperformed(actionevent playermove)     {         //get button pressed using getsource command         jbutton whatplayer=(jbutton)(playermove.getsource());              if(player == 1)             {                 player++;                 whatplayer.settext("player1");                 whatplayer.setenabled(false);                  validate();                  return;             }                            if (player == 2)             {                 player--;                 whatplayer.settext("player2");                 whatplayer.setenabled(false);                 validate();                  return;             }     }     public void validate()     {         if(button[0].gettext().equals(button[1].gettext()) && button[1].gettext().equals(button[2].gettext()))         {             joptionpane.showmessagedialog(null,"thank winner is" + button[0].gettext());             gameover();         }         if(button[3].gettext().equals(button[4].gettext()) && button[4].gettext().equals(button[5].gettext()))         {             joptionpane.showmessagedialog(null,"thank winner is" + button[3].gettext());             gameover();         }         if(button[6].gettext().equals(button[7].gettext()) && button[7].gettext().equals(button[8].gettext()))         {             joptionpane.showmessagedialog(null,"thank winner is" + button[6].gettext());             gameover();         }         if(button[0].gettext().equals(button[3].gettext()) && button[3].gettext().equals(button[6].gettext()))         {             joptionpane.showmessagedialog(null,"thank winner is" + button[0].gettext());             gameover();         }         if(button[1].gettext().equals(button[4].gettext()) && button[4].gettext().equals(button[7].gettext()))         {             joptionpane.showmessagedialog(null,"thank winner is" + button[1].gettext());             gameover();         }         if(button[1].gettext().equals(button[4].gettext()) && button[4].gettext().equals(button[7].gettext()))         {             joptionpane.showmessagedialog(null,"thank winner is" + button[1].gettext());             gameover();         }         if(button[2].gettext().equals(button[5].gettext()) && button[5].gettext().equals(button[8].gettext()))         {             joptionpane.showmessagedialog(null,"thank winner is" + button[2].gettext());             gameover();         }         if(button[0].gettext().equals(button[4].gettext()) && button[4].gettext().equals(button[8].gettext()))         {             joptionpane.showmessagedialog(null,"thank winner is" + button[0].gettext());             gameover();         }         if(button[2].gettext().equals(button[4].gettext()) && button[4].gettext().equals(button[6].gettext()))         {             joptionpane.showmessagedialog(null,"thank winner is" + button[2].gettext());             gameover();         }         if ( button.length == setenabled(false))  // problem.  don't know if worded correctly         {             joptionpane.showmessagedialog(null,"this draw");         }      }     public void gameover()     {         for( int x = 0; x < button.length; x++)         {             button[x].setenabled(false);         }     }   } public static void main(string[] arg) {     new tictactoe(); }    } 

button.length equal 9 since defined array of 9 elements

private static jbutton [] button = new jbutton[9]; 

how can if ( button.length == setenabled(false)) comparision in if loop, setenabled(false) going disable jframe , return type void,here comparing int void that's why error thrown @ compile time.

int i;  for(i=0;i<button.length;i++){      if(b[i].isenabled()){      break;      } }  if(i==button.length){ joptionpane.showmessagedialog(null,"this draw"); }