<div class="bo_w_tit write_div">
    <input type="checkbox" name="wr_4[]" value="인쇄" id="opt_1" />
    <label for="opt_1">인쇄</label>

    <input type="checkbox" name="wr_4[]" value="웹사이트" id="opt_2" />
    <label for="opt_2">웹사이트</label>

    <input type="checkbox" name="wr_4[]" value="영상" id="opt_3" />
    <label for="opt_3">영상</label>

    <input type="checkbox" name="wr_4[]" value="포장지" id="opt_4" />
    <label for="opt_4">포장지</label>

    <input type="checkbox" name="wr_4[]" value="임베딩" id="opt_5" />
    <label for="opt_5">임베딩</label>

    <input type="checkbox" name="wr_4[]" value="BI/CI" id="opt_6" />
    <label for="opt_6">BI/CI</label>

    <input type="checkbox" name="wr_4[]" value="OFL" id="opt_7" />
    <label for="opt_7">OFL</label>
</div>

 
 

for ($z=0; $z<count($_POST['wr_4']); $z++) {
    $a = $_POST['wr_4'];
    echo $a[$z];
}

 
계속 A라고만 나오네요..ㅠㅠ 왜그런걸까요?