is it possible if callback in array_filter receive parameter?
I got this multiple array named $files[]
, which consists of keys and values as below :
[0] => Array
(
[name] => index1.php
[path] => http://localhost/php/gettingstarted/
[number] => 1
)
[1] => Array
(
[name] => index10.php
[path] => http://localhost/php/gettingstarted/
[number] => 2
)
[2] => Array
(
[name] => index11.php
[path] => http://localhost/php/gettingstarted/
[number] => 3
)
I use this code to create a new array consist of 'name' keys only. But it failed
array_filter($files, "is_inarr_key('name')");
function is_inarr_key($a开发者_开发问答rray, $key)
{
//TODO : remove every array except those who got the same $key
}
and I get this error:
array_filter() [function.array-filter]: The second argument, 'is_inarr_key('name')', should be a valid callback in C:\xampp\htdocs\php\gettingstarted\index.php on line 15
So my questions are:
- Is it possible to make the call-back function on
array_filter
receive parameter? - What is the general rule of thumb on how to use callback in any PHP built-in function?
You can create a closure on PHP ≥5.3.
array_filter($files, function($array) use ($key) {
return is_inarr_key($array, $key);
} );
If you are stuck with PHP <5.3, …
You can make $key
a global variable.
function is_inarr_with_global_key($array) {
global $key;
....
}
You can create a class
class KeyFilter {
function KeyFilter($key) { $this->key = $key; }
function is_inarr_key($array) { ... }
}
...
array_filter($files, array(new KeyFilter('name'), 'is_inarr_key'));
You can create 3 different functions
array_filter($files, 'is_inarr_name');
array_filter($files, 'is_inarr_path');
array_filter($files, 'is_inarr_number');
You can write your own array_filter
function my_array_filter($files, $key) {
...
}
You can make use of the array_walk
function as:
$arr = array(
array("name" => "Jack", "id" => 1),
array("name" => "Rose", "id" => 2),
);
$result = array(); // initialize result array.
array_walk($arr, "filter"); // iterate over the array calling filter fun for each value.
// $result will now have elements "Jack" and "Rose"
function filter($a) {
global $result; // to access the global result array.
$result[] = $a['name']; // for each array passed, save the value for the key 'name' in the result array.
}
I am unaware if you can supply the callback function with parameters, but as a suggestion, you could define a callback function for array_filter
array_filter($files, "is_inarr_key");
And to get the name
of the array, just loop over the $file[]
and retrieve the name.
Then, having the name
you can go on with your logic.
HTH.
You can use create_function() in 5.2.x
$y = 5;
$func = 'return $x > ' . $y . ';';
$f = create_function('$x', $func);
$numbers = range(0, 10);
$result = array_filter($numbers, $f);
print_r($result);
which outputs
Array ( [6] => 6 [7] => 7 [8] => 8 [9] => 9 [10] => 10 )
thanks KennyTM for keyfilter class great tip. For those who care and don't know how to do it, this a working detailed example. I slightly improved using a regexp pattern.
$files[]= {code above};
class KeyFilter {
function KeyFilter($attr,$pattern)
{
$this->attr=$attr;
$this->pattern=$pattern;
}
function is_inarr_key($t)
{
return preg_match($this->pattern,$t[$this->attr]);;
}
}
$t=array_filter($items, array(new KeyFilter("path","~\d{2}\.php~i"), 'is_inarr_key'));
print_r($t);
print_r($o->key);
output:
[1] => Array
(
[name] => index**10**.php
[path] => http://localhost/php/gettingstarted/
[number] => 2
)
[2] => Array
(
[name] => index**11**.php
[path] => http://localhost/php/gettingstarted/
[number] => 3
)
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