Question

I am trying to understand the idea behind ArrayAccess Interface,

I dont understand what each method is about, If those methods(functions) are “built in” functions and ArrayAccess Interface(also “built in”) is only “make sure” i am going to implement those “built in” methods(functions)

I am trying to understand what does each of thoes functions is doing with our code “Behind the scenes”.

function offsetSet($offset, $value);
function offsetGet($offset);
function offsetUnset($offset);
function offsetExists($offset);

If i understand ArrayAccess is a Built In interface that Containing seals to implement, when we implement them we only implement references to thoes built in functions, I will be happy if some one can please help me get this right.

Answer 1

If you implement that interface, then the object acts like an array. e.g., if $foo is an instance of a class that implements ArrayAccess:

$foo['bar'] = 42 calls offsetSet('bar', 42).

echo $foo['bar'] calls offsetGet('bar').

unset($foo['bar']) calls offsetUnset('bar').

isset($foo['bar']) calls offsetExists('bar').

You never explicitly call the functions offset* yourself. It happens implicitly when you access the object as an array.