I have this
$ids = array_map(array($this, 'myarraymap'), $data['student_teacher']);
function myarraymap($item) {
return $item['user_id'];
}
I will would like to put an other parameter to my function to get something like
function myarraymap($item,$item2) {
return $item['$item2'];
}
Can someone can help me ? I tried lots of things but nothing work
You can use an anonymous function and transmit value of local variable into your myarraymap second argument this way:
function myarraymap($item,$item2) {
return $item[$item2];
}
$param = 'some_value';
$ids = array_map(
function($item) use ($param) { return myarraymap($item, $param); },
$data['student_teacher']
);
Normally it may be enough to just pass value inside anonymous function body:
function($item) { return myarraymap($item, 'some_value'); }
As of PHP 7.4, you can use arrow functions (which are basically short anonymous functions with a briefer syntax) for more succinct code:
$ids = array_map(
fn($item) => myarraymap($item, $param),
$data['student_teacher']
);
use($param)PHP's array_map() supports a third parameter which is an array representing the parameters to pass to the callback function. For example trimming the / char from all array elements can be done like so:
$to_trim = array('/some/','/link');
$trimmed = array_map('trim',$to_trim,array_fill(0,count($to_trim),'/'));
Much easier than using custom functions, or other functions like array_walk(), etc.
N.B. As pointed out in the comments below, I was a little hasty and the third param does indeed need to be same length as the second which is accomplished with array_fill().
The above outputs:
array(2) {
[0]=>
string(4) "some"
[1]=>
string(4) "link"
}
$trimmed = array_map('trim',array('/some/','/link'),array('/', '/'));
array_fill(0,count($to_trim), 'my params')
Apart from creating a mapper object, there isn't much you can do. For example:
class customMapper {
private $customMap = NULL;
public function __construct($customMap){
$this->customMap = $customMap;
}
public function map($data){
return $data[$this->customMap];
}
}
And then inside your function, instead of creating your own mapper, use the new class:
$ids = array_map(array(new customMapper('param2'), 'map'), $data['student_teacher']);
This will allow you to create a custom mapper that can return any kind of information... And you can complexify your customMapper to accept more fields or configuration easily.
Consider using the third parameter from array_map function to pass additional parameter to callable function. Example:
<?php
function myFunc($item, $param) {
echo $param . PHP_EOL;
}
$array = ['foo', 'bar'];
array_map('myFunc', $array, ['the foo param', 'the bar param']);
// the foo param
// the bar param
Ref: https://www.php.net/manual/en/function.array-map.php
The docs said about the third param from array_map function: "Supplementary variable list of array arguments to run through the callback function."
myFunc, it would be passed 'the param' only for the first element of $array. For subsequent elements it would be passed null because “if the arrays are of unequal length, shorter ones will be extended with empty elements to match the length of the longest.”
$item2to be? A constant value?array_mapis flawed. Could you provide a proper example?array_column(). 3v4l.org/ZQXPo See Is there a function to extract a 'column' from an array in PHP?