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Classes and Objects
Static Members

Instantiating objects is the most common way to use classes and is also the most in-line with OOP principles. Sometimes though, it can be useful to group a set of utility functions and variables together into a single class. Since these don’t change for every instance, we don’t need to instantiate them. We can use them statically.

When a member is intended to be used statically, we add the keyword static to its definition.

Consider this class with a static property and a static method:

class StringUtils { public static $max_number_of_characters = 80; public static function uclast($string) { $string[strlen($string)-1] = strtoupper($string[strlen($string)-1]); return $string; } }

Accessing these static members is done a little differently than with objects. We need to use the Scope Resolution Operator (::). This can be thought of as switching briefly into the scope of the class itself. Since we are inside the scope, we access properties with the dollar sign. For example:

echo StringUtils::$max_number_of_characters; # Prints "80"

Methods are accessed by using the method name:

echo StringUtils::uclast("hello world"); # Prints "hello worlD"

Instructions

1.

We’ve defined a utility class, AdamsUtils. Currently its members are not static.

Make $the_answer and addTowel static.

2.

Access both members of AdamsUtils statically and print them using echo. Pass $items as an argument for the static method.

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