PHP extract() Function: Importing Variables from an Array into the Symbol Table

The PHP extract() function imports variables from an associative array into the current symbol table, using the array keys as variable names and the corresponding values as variable values.

It checks each key for validity as a variable name and handles conflicts according to the $extract_type flag, which can be EXTR_OVERWRITE , EXTR_SKIP , EXTR_PREFIX_SAME , EXTR_PREFIX_ALL , EXTR_PREFIX_INVALID , EXTR_IF_EXISTS , EXTR_PREFIX_IF_EXISTS , or EXTR_REFS . If no flag is supplied, EXTR_OVERWRITE is assumed.

The optional $prefix parameter is used with the prefix‑related flags to prepend a string (and an underscore) to variable names, and it is ignored for other flags.

When successful, extract() returns the number of variables extracted; it returns FALSE for an empty array.

Example:

"blue",
    "size" => "medium",
    "shape" => "sphere"
);
extract($var_array, EXTR_PREFIX_SAME, "wddx");
echo "$color, $size, $shape, $wddx_size\n";
?>

The script outputs:

blue, large, sphere, medium