return result of foreach loop(s) - php

Question

I have the some code which looks something like this (I've simplified it):
function process_something($a){
foreach($a as $b){
// Some logic here
return $something;
}
}
$input=[]; // An array of some kind
echo process_something($input);
I expect that final line to echo what the loops have returned but I get nothing. Maybe the above code will not work. I just put it in for illustration. I have a lot of nested loops working together to return various things.
If I have the loops echo data out, it works. However, I need this function to just return the end result to me for further processing, rather than echoing out to the user.
How do I proceed?

Answer 1

In this case this loop will only run once, because return jumps out of a function on the first occurrence.
It should be more like:
function process_something($a){
foreach($a as $b){
$something = 'Some math or other logic here';
}
return $something;
}
$input=[]; // An array of some kind
echo process_something($input);
Please post your code, we will try to figure out what's wrong with it.

Answer 2

This is the perfect case for a generator, a concept that I rarely seen used.
function process_something($a){
foreach($a as $b){
// Some logic here
yield $something;
}
}
$input=[]; // An array of some kind
/**
* The generator returns an Iterator instance
* so you'd need to loop over it
*/
foreach(process_something($input) as $item){
// do stuff here
// echo $item
// echo $item->something
// your call
}
The major advantage here is that you can "return without actually returning", you're yielding a value and the generator continues on with it's work.
Not to mention it's very memory efficient, altough 99% of the times memory is not an issue.
AND, this is the nice part, you can apply specific logic for each of the items in the $input without needing to do some weird hack-ish function.
Alternatives
function process_something($a){
$return = [];
foreach($a as $b){
// Some logic here
$return[] = $something;
}
return $return;
}
The only reason this answer isn't a comment is that it's very rare that I see a question that would legitimately benefit from a generator. This is one of them.
More on generators:
http://blog.ircmaxell.com/2012/07/what-generators-can-do-for-you.html
https://scotch.io/tutorials/understanding-php-generators

Answer 3

I did get you properly . But I think you are looking for the last value of the array .
to do that just do it :
function process_something($a){
$b = array_reverse ($a);
return $b[0];
}

Answer 4

class StrHelper
{
/**
* Check for $string starts with $query
* #param $string
* #param $query
* #return bool
*/
public static function startsWith($string,$query){
return substr($string, 0, strlen($query)) === $query;
}
}
class ModelSearchHelper
{
/**
* filter where $key of $data arr startsWith $modelName
* #param string $modelName
* #param array $data
* #return array
*/
public static function searchFor(string $modelName,array $data){
// this code do same
// $out=[];
// foreach ($data as $key=>$value){
// if(StrHelper::startsWith($key,$modelName)){
// $out[$key]=$value;
// }
// }
// return $out;
// of this
return array_filter($data,function ($value,$key) use ($modelName){
return StrHelper::startsWith($key,$modelName);
},ARRAY_FILTER_USE_BOTH );
}
}
$test=[
'limit'=>10,
'offset'=>5,
'customer.name'=>'Fox',
'customer.address.street'=>'forest st.'
];
//filter where $key of $model startsWith $modelName
var_dump(ModelSearchHelper::searchFor('customer',$test));
result:
array(2) {
["customer.name"]=>
string(3) "Fox"
["customer.address.street"]=>
string(10) "forest st."
}