Question

我一定不知道如何处理PHP数组。当我执行以下代码时：

<?php
$ary = array(
  "alpha" => array("A"=>1,"B"=>2,"C"=>3),
  "beta" => array("A"=>7,"B"=>8,"C"=>9)
  );

foreach ($ary as $key => $vals) {
  $vals["B"]=99;
  echo $key."= ".$vals["A"]." ".$vals["B"]." ".$vals["C"]."<br>";
}
echo $ary['alpha']["B"]."<br>";
?>

我明白了：

alpha= 1 99 3
beta= 7 99 9
2

在每种情况下，对99的更改似乎都会丢失。我做错了什么？

Answer 1

如果要在foreach语句中更改数组项，则应通过引用传递。

foreach ($ary as $key => &$vals) {
}

Answer 2

<?php
$ary = array(
  "alpha" => array("A"=>1,"B"=>2,"C"=>3),
  "beta" => array("A"=>7,"B"=>8,"C"=>9)
  );

foreach ($ary as $key => $vals) {
  //$vals["B"]= 99;
  $ary[$key]["B"] = 99;
  echo $key."= ".$vals["A"]." ".$vals["B"]." ".$vals["C"]."<br>";
}
echo $ary['alpha']["B"]."<br>";
?>

更改多维关联数组PHP中的值

2 个答案: