# The ArrayAccess interface

(PHP 5, PHP 7)

## Introduction

Interface to provide accessing objects as arrays.

## Interface synopsis

ArrayAccess {
/* Methods */
abstract public offsetExists ( mixed `$offset` ) : bool
abstract public offsetGet ( mixed `$offset` ) : mixed
abstract public offsetSet ( mixed `$offset` , mixed `$value` ) : void
abstract public offsetUnset ( mixed `$offset` ) : void
}

Example #1 Basic usage

`<?php
class Obj implements ArrayAccess {
private $container = array();
public function __construct() {
$this->container = array(
"one" => 1,
"two" => 2,
"three" => 3,
);
}
public function offsetSet($offset, $value) {
if (is_null($offset)) {
$this->container[] = $value;
} else {
$this->container[$offset] = $value;
}
}
public function offsetExists($offset) {
return isset($this->container[$offset]);
}
public function offsetUnset($offset) {
unset($this->container[$offset]);
}
public function offsetGet($offset) {
return isset($this->container[$offset]) ? $this->container[$offset] : null;
}
}
$obj = new Obj;
var_dump(isset($obj["two"]));
var_dump($obj["two"]);
unset($obj["two"]);
var_dump(isset($obj["two"]));
$obj["two"] = "A value";
var_dump($obj["two"]);
$obj[] = 'Append 1';
$obj[] = 'Append 2';
$obj[] = 'Append 3';
print_r($obj);
?>`

The above example will output something similar to:

    bool(true)
    int(2)
    bool(false)
    string(7) "A value"
    obj Object
    (
        [container:obj:private] => Array
            (
                [one] => 1
                [three] => 3
                [two] => A value
                [0] => Append 1
                [1] => Append 2
                [2] => Append 3
            )

    )

## Table of Contents

- ArrayAccess::offsetExists — Whether an offset exists
- ArrayAccess::offsetGet — Offset to retrieve
- ArrayAccess::offsetSet — Assign a value to the specified offset
- ArrayAccess::offsetUnset — Unset an offset