Update traits.xml Mention the hierarchy of classes, amend final modifier example

language/oop5/traits.xml

@@ -425,23 +425,29 @@ Example::doSomething();
     <title>Static Properties</title>
     <caution>
      <simpara>
-      Prior to PHP 8.3.0, static properties were shared across all classes
-      using the trait. As of PHP 8.3.0, each class using the trait has its
-      own copy of the static property.
+      Prior to PHP 8.3.0, static properties defined in a trait were shared across a single hierarchy of classes
+      which use the trait. As of PHP 8.3.0, each class using the trait has its
+      own copy of the static property if it explicitly uses the trait,
+      i.e. the static property defined in a trait inserted into a child class override
+      a static property that the child class inherited from the parent class.
      </simpara>
     </caution>
     <programlisting role="php">
      <![CDATA[
 <?php
-trait StaticExample {
+
+trait StaticExample
+{
     public static $static = 'foo';
 }
 
-class Example {
+class Example
+{
     use StaticExample;
 }
 
 echo Example::$static;
+
 ?>
 ]]>
     </programlisting>
@@ -458,16 +464,20 @@ echo Example::$static;
     <programlisting role="php">
 <![CDATA[
 <?php
-trait PropertiesTrait {
+
+trait PropertiesTrait
+{
     public $x = 1;
 }
 
-class PropertiesExample {
+class PropertiesExample
+{
     use PropertiesTrait;
 }
 
-$example = new PropertiesExample;
+$example = new PropertiesExample();
 $example->x;
+
 ?>
 ]]>
     </programlisting>
@@ -556,26 +566,37 @@ class ConstantsExample {
   <title>Final methods</title>
   <simpara>
    As of PHP 8.3.0, the <link linkend="language.oop5.final">final</link>
-   modifier can be applied to methods coming from traits.
+   modifier can be applied to methods coming from traits by same syntax with the <literal>as</literal> operator
+   which modifies traits' methods visibility in classes.
   </simpara>
   <example xml:id="language.oop5.traits.final-methods.example">
    <title>Defining a method coming from a trait as <literal>final</literal></title>
    <programlisting role="php">
     <![CDATA[
 <?php
-trait ConstantsTrait {
-    public function method() {
+
+trait CommonTrait
+{
+    public function method()
+    {
         echo 'Hello';
     }
 }
 
-class ConstantsExample {
-    use ConstantsTrait;
-
-    final public function method() {
-        echo 'Hello World';
+class FinalExampleA
+{
+    use CommonTrait {
+        CommonTrait::method as final; // The 'final' will prevents child classes
+                                      // from overriding a method
     }
 }
+
+class FinalExampleB extends FinalExampleA
+{
+     public function method() {} // Fatal error: Cannot override final method
+                                 // FinalExampleA::method()
+}
+
 ?>
 ]]>
    </programlisting>