PHP extract() Function

extract(array,extract_rules,prefix)

Possible values:

• EXTR_OVERWRITE - Default. On collision, the existing variable is overwritten
• 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

This parameter specifies the prefix. The prefix is automatically separated from the array key by an underscore character.

<?php
$a = 'Original';
$my_array = array("a" => "Cat","b" => "Dog", "c" => "Horse");
extract($my_array);
echo "\$a = $a; \$b = $b; \$c = $c";
?>

$a = Cat; $b = Dog; $c = Horse

<?php
$a = 'Original';
$my_array = array("a" => "Cat","b" => "Dog", "c" => "Horse");

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

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

$a = Original; $b = Dog; $c = Horse; $dup_a = Cat;