rookie PHP question, what does -> represent?

I am a rookie with PHP, w开发者_如何学运维hat does this do ->? i tried Google and searching the forums but nothing came up. for instance, i have seen "$resp->is_valid" used but not sure what it does. Thanks

If you have an instance of an object, then -> accesses a property or method inside that object.

For example:

$mysqli_object = new mysqli( ... );
$mysqli_statement = $mysqli_object->prepare( ... );
// calls the prepare() method of mysqli_object

The -> operator is similar to the :: operator in that both access something inside a class. However, :: is for accessing things for objects that do not need to be instantiated:

$sum = MySumClass::sum( ... ); 
// I don't need to first create an instance (using "new") of
// MySumClass before using it because MySumClass::sum() is static

In PHP -> is used to access a property (or method) of an object. You can read more here:

http://php.net/manual/en/sdo.sample.getset.php

It returns the member variable $is_valid of the object referred to by $resp