PHP Reference
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Quick Reference

The PHP extract() function uses array keys as variable names and values as variable values to import variables into the local symbol table from an array.

<?php
$a = 'Lamborghini';
$my_array = array('a' => 'Ferrari', 'b' => 'Maserati', 'c' => 'Alfa Romeo');

extract($my_array, EXTR_PREFIX_SAME, 'dup');

echo "\$a = $a - \$b = $b - \$c = $c - \$dup_a = $dup_a";
?>

Note

Arrays count starting from zero NOT one. So item 1 is position [0], item 2 is position [1], and item 3 is position [2] … and so on.

Output

$a = Lamborghini - $b = Maserati - $c = Alfa Romeo - $dup_a = Ferrari

Syntax

extract(array, extract_rules, prefix)

Parameters

ParameterDescription
arraySpecifies an array (required)
extract_rulesThe extract() function checks for invalid variable names and collisions with existing variable names; this parameter specifies how invalid and colliding names are treated

  • EXTR_OVERWRITE - On collision, the existing variable is overwritten (default)

  • EXTR_SKIP - On collision, the existing variable is not overwritten

  • EXTR_PREFIX_SAME - On collision, the variable name will be given a prefix

  • EXTR_PREFIX_ALL - All variable names will be given a prefix

  • EXTR_PREFIX_INVALID - Only invalid or numeric variable names will be given a prefix

  • EXTR_IF_EXISTS - Only overwrite existing variables in the current symbol table, otherwise do nothing

  • EXTR_PREFIX_IF_EXISTS - Only add prefix to variables if the same variable exists in the current symbol table

  • EXTR_REFS - Extracts variables as references. The imported variables are still referencing the values of the array parameter
prefixThis parameter specifies the prefix; the prefix is automatically separated from the array key by an underscore character

If EXTR_PREFIX_SAME, EXTR_PREFIX_ALL, EXTR_PREFIX_INVALID or EXTR_PREFIX_IF_EXISTS are used in the extract_rules parameter, a specified prefix is required

PHP Notes:

  • When using PHP, single or double quotation marks are acceptable and work identically to one another; choose whichever you prefer, and stay consistent
  • Arrays count starting from zero NOT one; so item 1 is position [0], item 2 is position [1], and item 3 is position [2] … and so on
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