php数组怎么根据值获取键名？

array_search(value,array,strict)

<?php
$items = array(
    "banana" => "fruit",
    "tomato" => "vegetable",
    "lentil" => "bean",
    "apple"  => "vegetable"
);
 
//1.返回一个键名，如果值有重复返回第一个键名
$key = array_search(&#39;vegetable&#39;, $items);
 
echo $key;//tomato

?>

tomato

array_keys(array,value,strict)

<?php
$items = array(
    "banana" => "fruit",
    "tomato" => "vegetable",
    "lentil" => "bean",
    "apple"  => "vegetable"
);
//2.返回多个键名
$keys=array_keys($items,&#39;vegetable&#39;);
 
print_r($keys);
?>

Array ( [0] => tomato [1] => apple )