Arrayaccess (array-access) interface

Interface Summary Arrayaccess {/* method */abstract public boolean offsetexists (mixed $offset) abstract public mixed offsetget (mixed $o Ffset) abstract public void Offsetset (mixed $offset, mixed $value) abstract public void Offsetunset (mixed $offset)}

As an example,

class test implements arrayaccess{    private  $testData  = [] ;     public function offsetexists ($offset)     {         echo  ' call  '  . __METHOD__ .  ' \ r \ n ';         return isset ($this->testdata[$offset]);     }    public function offsetget ($offset)     {         echo  ' call  '  . __METHOD__ .  ' \ r \ n ';         return  $this->testdata[$offset];     }    public function offsetset ($offset,  $value)      {        echo  ' call  '  . __method__ .   "\ r \ n";         return  $this->testdata[$offset] =  $value;     }     public function offsetunset ($offset)     {         echo  ' call  '  . __METHOD__ .  ' \ r \ n ';         unset ($this->testdata[$offset]);     }}

$obj = new Test ();

if (!isset ($obj [' name '])) {//call test::offsetexists
$obj [' name '] = ' zhangsan '; Call Test::offsetset
}
echo $obj [' name '].    "\ r \ n"; Call Test::offsetget

Var_dump ($obj);

$obj [' age '] = 18; Call Test::offsetset

echo $obj [' age '].    "\ r \ n"; Call Test::offsetget

unset ($obj [' address ']); Call Test::offsetunset

Arrayaccess (array-access) interface