嵌套前（）

php arrays loops foreach

2022-08-31 01:00:23

我有以下数组：

Array ( 
  [1] => Array ( 
    [spubid] => A00319 
    [sentered_by] => pubs_batchadd.php
    [sarticle] => Lateral mixing of the waters of the Orinoco, Atabapo
    [spublication] => Acta Cientifica Venezolana
    [stags] => acta,confluence,orinoco,rivers,venezuela,waters
    [authors] => Array ( 
      [1] => Array ( 
        [stype] => Author 
        [iorder] => 1 
        [sfirst] => A
        [slast] => Andersen ) 
      [2] => Array ( 
        [stype] => Author 
        [iorder] => 2 
        [sfirst] => S.
        [slast] => Johnson ) 
      [3] => Array ( 
        [stype] => Author 
        [iorder] => 3 
        [sfirst] => J. 
        [slast] => Doe ) 
      ) 
    ) 
  )

我正在使用嵌套的foreach（）来遍历外部数组中的元素，但是当涉及到吐出作者列表时，我遇到了问题。也就是说，由于疯狂的foreach（）嵌套，输出每个一个多次（多次）次的问题。在此示例中，有什么比嵌套 foreach（）循环更好的方法？

更新（带解决方案）

这是我确定的循环，有点混乱（恕我直言），但它有效：

$sauthors = NULL;
$stitle = NULL;

foreach($apubs as $apub)
{
  $stitle = $apub['sarticle'];
  foreach($apub as $svar=>$sval)
  {
    if($svar === "authors")
    {
      foreach($sval as $apeople)
      {
        $sauthors .= $apeople['slast'].", ".$apeople['sfirst']."; ";
      }
    }
  }
  echo "$sauthors<br />\n$stitle<br />\n";
}

答案 1

你为什么不这样做

foreach($apubs as $apub) {
  $sauthors = '';
  $stitle = $apub['sarticle'];
  foreach($apub['authors'] as $author) {
    $sauthors .= $author['slast'].", ".$author['sfirst']."; ";
  }

  echo "$sauthors<br />\n$stitle<br />\n";
}

答案 2

只是为了好玩。如果你真的想避免循环，试试这个：

// Pre PHP 5.3:

function cb2($e)
{
    return $e['slast'] . ', ' . $e['sfirst'];
}

function cb1($e)
{
    $authors = array_map('cb2', $e['authors']);
    echo implode('; ', $authors) . ":<br />\n" . $e['sarticle'] . "<br />\n";
}

array_walk($data, 'cb1');



// PHP 5.3 (untested):

array_walk($data, function($e)
{
    $authors = array_map(function($e)
    {
        return $e['slast'] . ', ' . $e['sfirst'];
    },
    $e['authors']);

    echo implode('; ', $authors) . ":<br />\n" . $e['sarticle'] . "<br />\n";
});