Exception updates

language/exceptions.xml

@@ -188,22 +188,43 @@ echo "\n\n";
     of potential exceptions. Each &try; must have at least one corresponding
     &catch; or &finally; block.
    </para>
-
+   <para>
+    If an exception is thrown and its current function scope has no &catch;
+    block, the exception will "bubble up" the call stack to the calling
+    function until it finds a matching &catch; block.  All &finally; blocks it encounters
+    along the way will be executed. If the call stack is unwound all the way to the
+    global scope without encountering a matching &catch; block, the program will
+    terminate with a fatal error.
+   </para>
    <para>
     The thrown object must be an instance of the
     <classname>Exception</classname> class or a subclass of
     <classname>Exception</classname>. Trying to throw an object that is not
     will result in a PHP Fatal Error.
    </para>
+   <para>
+    As of PHP 8.0.0, the &throw; keyword is an expression and may be used in any expression
+    context. In prior versions it was a statement and must be on its own line.
+   </para>
+
   </simplesect>
 
   <simplesect xml:id="language.exceptions.catch">
    <title><literal>catch</literal></title>
+   <para>
+    A &catch; block defines how to respond to a thrown exception.  A &catch;
+    block defines one or more types of exception or error it can handle, and
+    optionally a variable to which to assign the exception. (The variable was
+    required prior to PHP 8.0.0.)  The first &catch; block a thrown exception
+    or error encounters that matches the type of the thrown object will handle
+    the object.
+   </para>
    <para>
     Multiple &catch; blocks can be used to catch different classes of
     exceptions. Normal execution (when no exception is thrown within the &try;
     block) will continue after that last &catch; block defined in sequence.
-    Exceptions can be &throw;n (or re-thrown) within a &catch; block.
+    Exceptions can be &throw;n (or re-thrown) within a &catch; block. If not,
+    execution will continue after the &catch; block that was triggered.
    </para>
    <para>
     When an exception is thrown, code following the statement will not be
@@ -213,11 +234,16 @@ echo "\n\n";
     been defined with <function>set_exception_handler</function>.
    </para>
    <para>
-    In PHP 7.1 and later, a &catch; block may specify multiple exceptions
+    As of PHP 7.1.0, a &catch; block may specify multiple exceptions
     using the pipe (<literal>|</literal>) character. This is useful for when
     different exceptions from different class hierarchies are handled the
     same.
    </para>
+   <para>
+    As of PHP 8.0.0, the variable name for a caught exception is optional.
+    If not specified, the &catch; block will still execute but will not
+    have access to the thrown object.
+   </para>
   </simplesect>
 
   <simplesect xml:id="language.exceptions.finally">
@@ -435,6 +461,52 @@ string(11) "MyException"
 ]]>
     </screen>
    </example>
+   <example>
+    <title>Omitting the caught variable</title>
+    <para>Only permitted in PHP 8.0.0 and later.</para>
+    <programlisting role="php">
+<![CDATA[
+<?php
+
+class SpecificException extends Exception {}
+
+function test() {
+    throw new SpecificException('Oopsie');
+}
+
+try {
+    test();
+}
+catch (SpecificException) {
+    print "A SpecificException was thrown, but we don't care about the details.";
+}
+?>
+]]>
+    </programlisting>
+   </example>
+   <example>
+    <title>Throw as an expression</title>
+    <para>Only permitted in PHP 8.0.0 and later.</para>
+    <programlisting role="php">
+<![CDATA[
+<?php
+
+class SpecificException extends Exception {}
+
+function test() {
+    do_something_risky() or throw new Exception('It did not work');
+}
+
+try {
+    test();
+}
+catch (Exception $e) {
+    print $e->getMessage();
+}
+?>
+]]>
+    </programlisting>
+   </example>
   </simplesect>
 
  </chapter>