The double arrow operator,
=>, is used as an access mechanism for arrays. This means that what is on the left side of it will have a corresponding value of what is on the right side of it in array context. This can be used to set values of any acceptable type into a corresponding index of an array. The index can be associative (string based) or numeric.
$myArray = array( 0 => 'Big', 1 => 'Small', 2 => 'Up', 3 => 'Down' );
The object operator,
->, is used in object scope to access methods and properties of an object. It’s meaning is to say that what is on the right of the operator is a member of the object instantiated into the variable on the left side of the operator. Instantiated is the key term here.
// Create a new instance of MyObject into $obj $obj = new MyObject(); // Set a property in the $obj object called thisProperty $obj->thisProperty = 'Fred'; // Call a method of the $obj object named getProperty $obj->getProperty();