PHP array introductory tutorial array_keys() function

This article introduces the usage of the array_keys() function in PHP arrays. Friends in need can refer to it.

In php array functions, array_keys() function returns an array containing all the keys found in the searched array.

The form is as follows: array array_keys(array array[,mixed search_value])

If the optional parameter search_value is included, only keys matching that value will be returned.

Example that will output all arrays found in the $fruit array:

<?php
$fruits["apple"] = "red";  
$fruits["banana"] = "yellow";  
$fruits["watermelon"]="green";  
$keys = array_keys($fruits);  
print_r($keys);  //by bbs.it-home.org
  
//Array ( [0] => apple [1] => banana [2] => watermelon )
?>