Php 仅回显唯一值

我有一个打印新闻稿的XML文件。我想回应新闻稿发布的所有年份，就像档案一样。只有唯一的值。下面的代码打印出所有年份。类似于“20172017201720162016201520152014”，而非“20172016201520142013”

---

记下已经打印的日期

$printed = [];

foreach ($xml->Releases as $release) {
    $year = date('Y', strtotime($release['PublishDateUtc']));

    if (!isset($printed[$year])) {
        echo $year;
        $printed[$year] = $year;
    }
}

---

记下已经打印的日期

$printed = [];

foreach ($xml->Releases as $release) {
    $year = date('Y', strtotime($release['PublishDateUtc']));

    if (!isset($printed[$year])) {
        echo $year;
        $printed[$year] = $year;
    }
}

试试这个

<?php
$file        = "file.xml";
$xml         = simplexml_load_file($file);
$yearArray   = array();
$uniqueArray = array();
foreach ($xml->Release as $release) {
    $date        = $release['PublishDateUtc'];
    /* $date is now in format yyyy-mm-ddT06:30:00 */
    $year        = substr($date, 0, 4);
    $yearArray[] = $year;
}

$uniqueArray = array_unique($yearArray);
print_r($uniqueArray);
?>

初始化2个额外变量，并在循环内生成年数组。然后打印唯一数组。

试试这个

<?php
$file        = "file.xml";
$xml         = simplexml_load_file($file);
$yearArray   = array();
$uniqueArray = array();
foreach ($xml->Release as $release) {
    $date        = $release['PublishDateUtc'];
    /* $date is now in format yyyy-mm-ddT06:30:00 */
    $year        = substr($date, 0, 4);
    $yearArray[] = $year;
}

$uniqueArray = array_unique($yearArray);
print_r($uniqueArray);
?>

---

初始化2个额外变量，并在循环内生成年数组。然后打印唯一数组。

值是否始终按顺序排列？然后只需将最后一个值存储在变量中，并且仅当最后一个值不等于当前值时才回显。这些值是否始终按顺序排列？然后，只需将最后一个值存储在变量中，并且仅在最后一个值不等于当前值时进行echo。您可以执行

echo$printed[$year]=$year

，保存一行代码。谢谢，这对我帮助很大！你可以做

echo$printed[$year]=$year

，保存一行代码。谢谢，这对我帮助很大！