ขอความช่วยเหลือ แนะนำ การเปรียบเทียบระหว่าง 2 Array หน่อยคับ

<?php
$array1 = array("a" => "green", "red", "blue", "red");
$array2 = array("b" => "green", "yellow", "red");
$result = array_diff($array1, $array2);

print_r($result);
?>

if($actionExam=="EditExamSet" || $actionExamPost=="EditExamSet"){
						$sql_Exam_set_compare = "Select * From test_set Where ts_id = '$ExamSetIDPost'";
						$result_sql_Exam_set_compare = mysql_query($sql_Exam_set_compare);
						while($rs_Exam_compare = mysql_fetch_array($result_sql_Exam_set_compare)){
							$Exam_Emp[] = $rs_Exam_compare['emp_id'];
							$Exam_Emu[] = $rs_Exam_compare['emu_id'];
							$Exam_Efb[] = $rs_Exam_compare['efb_id'];
							$Exam_Ext[] = $rs_Exam_compare['ext_id'];
						}
						$emu_num2 = array_sum($emu_num);
						$Exam_Emu_num=0;
						for($i=1;$i<count($emu_num);$i++){
							$objectID[] = $_POST['emu_objID'.$i];
							if($emu_num[$i]==""){
								$emu_num[$i] = 0;
							}else{
								$emu_num[$i];
							}
							if($emu_num[$i]!=0){
								if($i>count($Exam_Emu)){
									break;
								}
								$sql_Exam_rendom_emu = "Select * From objective_test Where obj_id='$objectID[$Exam_Emu_num]' And emu_id!=0 ORDER BY RAND() LIMIT $emu_num2";
								$result_emu_show = mysql_query($sql_Exam_rendom_emu);
								$result_emu_show_num_row[] = mysql_num_rows($result_emu_show);
								while($rs_emu_show = mysql_fetch_array($result_emu_show)){
									$emuID_show3[] = $rs_emu_show['emu_id'];
								}
							}
								
							$Exam_Emu_num++;
						}
						echo  $resultArray = array_diff($emuID_show3, $Exam_Emu);
					}