PHP - Function extract()

Syntax

extract($array, $extract_type, $prefix)

Definition and Usage

This function is used to import variables from an array into the current symbol table. It takes an associative array array and treats keys as variable names and values as variable values. For each key/value pair it will create a variable in the current symbol table, subject to extract_type and prefix parameters.

Parameters

Sr.No	Parameter & Description
1	array(Required) It specifies an array
2	extract_type(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.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
3	prefix(Optional) 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. This parameter specifies the prefix. The prefix is automatically separated from the array key by an underscore character.

Sr.No

Parameter & Description

array(Required)

It specifies an array

extract_type(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.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

prefix(Optional)

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.

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

Return Value

It returns the number of variables successfully imported into the symbol table.

Example

Try out following example −

Live Demo

<?php
   $size = "large";
   $input = array("color" => "blue", "size"  => "medium", "shape" => "sphere");
   extract($input, EXTR_PREFIX_SAME, "bbcx");
   echo "$color, $size, $shape, $bbcx_size";
?>

This will produce the following result −

blue, large, sphere, medium

php_function_reference.htm