PHP extract()

The extract() method imports variables into the current symbol table from an array.

Syntax

extract($array, flags, prefix)

The extract() function has one required parameter and some optional parameters:

• $array: Specifies the input array.
• flags: Optional. The extract() function checks for invalid variable names and collisions with existing variable names. This parameter specifies how invalid and colliding names are treated. Below are 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 overwrites existing variables in the current symbol table, otherwise does nothing.
  • EXTR_PREFIX_IF_EXISTS: Only adds prefix to variables if the same variable exists in the current symbol table.
  • EXTR_REFS: Extracts variables as references.
• prefix: Optional. If EXTR_PREFIX_SAME, EXTR_PREFIX_ALL, EXTR_PREFIX_INVALID or EXTR_PREFIX_IF_EXISTS are used in the flags parameter, a specified prefix is required.

The extract() function returns the number of variables extracted on success.

Example

The following example demonstrates an implementation of the extract() function:

<?php
  $a = "Original";
  $my_array = array("a" => "Rat","b" => "Mule", "c" => "Ass");
  extract($my_array);
  echo "\$a = $a; \$b = $b; \$c = $c";
?>

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The example will result in the following output:

$a = Rat; $b = Mule; $c = Ass

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Codebyte Example

This example is runnable and uses the extract() function:

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