php - 如何在 php 中打印或回显数组？

Question

<?php
$tiger = array ("orange", "white");
$cat = array ("black", "white", "brown");
$fruit = array ("purple", "red", "green", "brown");
?>

如何输出类似：

orange : tiger
white  : tiger + cat
black  : cat
brown  : cat + fruit
purple : fruit

Answer 1

数组的一点乐趣：

$arrays = compact('tiger', 'cat', 'fruit');
$values = array_unique(call_user_func_array('array_merge_recursive', $arrays));

foreach ($values as $value) {
    $found = array();
    foreach ($arrays as $name => $bag) {
        if (in_array($value, $bag)) {
            $found[] = $name;
        }
    }
    echo "$value: ".implode(", ", $found)."\n";
}

您可以通过修改第一行轻松地将其扩展到任意数量的数组。

看到它在行动。

Answer 2

因此，您似乎对获取各种对象的颜色感兴趣，并切换关联以使颜色反映对象，而不是相反。

这是一种适用于您的场景的方法：

<?php
// The objects we wish to extract colors for
$subjects = array(
  'tiger' => array ("orange", "white"),
  'cat' => array ("black", "white", "brown"),
  'fruit' => array ("purple", "red", "green", "brown")
);

// The array we will push colors to as keys, and objects to as values
$consolidated = array();

// Iterate over each object
foreach($subjects as $subject => $colors) {
  // Iterate over each color in the object
  foreach($colors as $color) {
    $consolidated[$color][] = $subject;
  }
}

// Print out results.
foreach($consolidated as $subject => $contents) {
  print $subject . ' : ' . implode(' + ', $contents) . "<br />\n";
}

上述输出：

orange : tiger
white : tiger + cat
black : cat
brown : cat + fruit
purple : fruit
red : fruit
green : fruit