Question

我是PHP的新手，并且想要做一个foreach循环，如果之前输出了相同的项目，则不会重复结果。

这是我的代码：

    foreach ( $attachments as $id => $attachment ) {
        echo ($attachment->post_title);
    }

正如您所看到的，这个词会被echo ($attachment->post_title);拉出来。

有没有办法做一些检查并避免重复？

非常感谢你的帮助。

Answer 1

$outputted = array();

foreach($attachments as $id => $attachment) {
   if (!isset($outputted[$attachment->post_title])) {
      echo $attachment->post_title;
      $outputted[$attachment->post_title] = true;
   }
}

Answer 2

您可以像Rajesh建议的那样使用array_unique，而不必担心制作额外的阵列。

foreach ( array_unique($attachments) as $id => $attachment ) {
        echo ($attachment->post_title);
}

Answer 3

foreach ( $attachments as $id => $attachment ) {

         if (!isset($outputs[$attachment->post_title])){
            $outputs[$attachment->post_title] = true;
            echo ($attachment->post_title);
         }
}

Answer 4

你可以这样做：

$output = array();

foreach ( $attachments as $id => $attachment ) {
    if (!isset($output[$attachment->post_title])){
        echo ($attachment->post_title);
        $output[$attachment->post_title] = true;
    }
}

Answer 5

使用关联数组：

$used = array();
foreach ($attachments as $id => $attachment) {
    if (!array_key_exists($attachment->post_title, $used)) {
        $used[$attachment->post_title] = 1;
        echo $attachment->post_title;
    }
}

Answer 6

也许是这样的？

foreach ( $attachments as $id => $attachment ) {
    $attachments_posted[] = $attachment;
    if (!array_search($attachment, $attachments_posted))
        echo ($attachment->post_title);
}

Answer 7

使用数组来跟踪您已经看过的标题：

$seen = array();
foreach ($attachments as $id => $attachment) {
    if (array_key_exists($attachment->post_title, $seen)) {
        continue;
    }
    $seen[$attachment->post_title] = true;
    echo $attachment->post_title;
}

如果单个单词已经输出，继续

7 个答案: