Functional Helpers

Column Extract

array_column extracts one named field from each row.

one field from many rows Column extraction turns a list of records into a list of selected values.

Column Extract

field
column_extract.php
Replay: real traced execution (multi-file project)
<?php
$field = "name";
$rows = [
    ["name" => "Ada", "city" => "London", "role" => "admin"],
    ["name" => "Rasmus", "city" => "Copenhagen", "role" => "author"]
];
$values = array_column($rows, $field);
$summary = implode(",", $values);

echo "field=" . $field . "\n";
echo "values=" . $summary . "\n";

<?php
$field = "city";
$rows = [
    ["name" => "Ada", "city" => "London", "role" => "admin"],
    ["name" => "Rasmus", "city" => "Copenhagen", "role" => "author"]
];
$values = array_column($rows, $field);
$summary = implode(",", $values);

echo "field=" . $field . "\n";
echo "values=" . $summary . "\n";

<?php
$field = "role";
$rows = [
    ["name" => "Ada", "city" => "London", "role" => "admin"],
    ["name" => "Rasmus", "city" => "Copenhagen", "role" => "author"]
];
$values = array_column($rows, $field);
$summary = implode(",", $values);

echo "field=" . $field . "\n";
echo "values=" . $summary . "\n";

  1. $field ← name, $rows ← Array, $values ← Array, $summary ← Ada,Rasmus

    1<?php2$field→ name = "name"; //@field="city", "role"3$rows→ Array = [4    ["name" => "Ada", "city" => "London", "role" => "admin"],5    ["name" => "Rasmus", "city" => "Copenhagen", "role" => "author"]6];7$values→ Array = array_column($rowsArray, $fieldname);8$summary→ Ada,Rasmus = implode(",", $valuesArray);910echo "field=" . $fieldname . "\n";11echo "values=" . $summaryAda,Rasmus . "\n";
    outputfield=name
values=Ada,Rasmus

  1. $field ← city, $rows ← Array, $values ← Array, $summary ← London,Copenhagen

    1<?php2$field→ city = "city";3$rows→ Array = [4    ["name" => "Ada", "city" => "London", "role" => "admin"],5    ["name" => "Rasmus", "city" => "Copenhagen", "role" => "author"]6];7$values→ Array = array_column($rowsArray, $fieldcity);8$summary→ London,Copenhagen = implode(",", $valuesArray);910echo "field=" . $fieldcity . "\n";11echo "values=" . $summaryLondon,Copenhagen . "\n";
    outputfield=city
values=London,Copenhagen

  1. $field ← role, $rows ← Array, $values ← Array, $summary ← admin,author

    1<?php2$field→ role = "role";3$rows→ Array = [4    ["name" => "Ada", "city" => "London", "role" => "admin"],5    ["name" => "Rasmus", "city" => "Copenhagen", "role" => "author"]6];7$values→ Array = array_column($rowsArray, $fieldrole);8$summary→ admin,author = implode(",", $valuesArray);910echo "field=" . $fieldrole . "\n";11echo "values=" . $summaryadmin,author . "\n";
    outputfield=role
values=admin,author