Added intial Type Declarations docs PHP 7

Added Functions changelog

git-svn-id: https://svn.php.net/repository/phpdoc/en/trunk@337104 c90b9560-bf6c-de11-be94-00142212c4b1

language/functions.xml

@@ -176,7 +176,36 @@ function recursion($a)
     Information may be passed to functions via the argument list,
     which is a comma-delimited list of expressions. The arguments are
     evaluated from left to right.
-   </simpara> 
+   </simpara>
+   <para>
+      <informaltable>
+       <tgroup cols="2">
+        <thead>
+         <row>
+          <entry>&Version;</entry>
+          <entry>&Description;</entry>
+         </row>
+        </thead>
+        <tbody>
+         <row>
+          <entry>5.1.0</entry>
+          <entry>classes,interfaces and arrays type declaration</entry>
+         </row>
+         <row>
+          <entry>5.4.0</entry>
+          <entry><type>callable</type> type declaration</entry>
+         </row>
+         <row>
+          <entry>7.0.0</entry>
+          <entry>scalar (<type>int</type>, 
+           <type>float</type>, 
+           <type>string</type>, 
+           <type>bool</type>) type declaration</entry>
+         </row>
+        </tbody>
+       </tgroup>
+      </informaltable>
+     </para>  
    <para>
     PHP supports passing arguments by value (the default), <link
     linkend="functions.arguments.by-reference">passing by
@@ -199,8 +228,7 @@ function takes_array($input)
 ]]>
      </programlisting>
     </example>
-   </para>
- 
+   </para>   
    <sect2 xml:id="functions.arguments.by-reference">
     <title>Making arguments be passed by reference</title>
  
@@ -232,9 +260,7 @@ echo $str;    // outputs 'This is a string, and something extra.'
       </programlisting>
      </example>
     </para>
- 
    </sect2>
- 
    <sect2 xml:id="functions.arguments.default">
     <title>Default argument values</title>
  
@@ -356,9 +382,143 @@ Making a bowl of acidophilus raspberry.
       As of PHP 5, arguments that are passed by reference may have a default value.
      </simpara>
     </note>
-
    </sect2>
+   <sect2 xml:id="functions.scalar-type-declaration">
+    <title>Scalar Type Declaration</title>
+    <para>
+    <note>
+     <para>
+      Type declaration is also known as Type Hinting.
+     </para>
+    </note>
+     PHP 7 introduces scalar type declaration. Functions are now able to force parameters
+     to be <type>string</type>, <type>int</type>, <type>float</type> or <type>bool</type>.
+     By default all PHP Files are in weakly typed mode. 
+     To enable strict type checking, <link linkend="control-structures.declare">declare(strict_types=1)</link>
+     directive must be the first
+     statement in the file. strict_types has two options, 1 for strict type
+     checking and 0 for weak type checking. This only affects the file this is stated in and not
+     files either included in this file or other files that include this file.
+     Whether or not the function being called was declared in a file that uses strict or weak 
+     type checking is irrelevant. The type checking mode depends on the file where the function is called from.
+    </para>
+    <para>
+     <example>
+      <title>Scalar Type Declaration examples</title>
+       <programlisting role="php">
+<![CDATA[
+<?php
+declare(strict_types=1); // Fatal error if this is not the first statement
+include "foo.php";
 
+foo(); // strictly type-checked function call
+
+function foobar() {
+    foo(); // strictly type-checked function call
+}
+ 
+class baz {
+    function foobar() {
+        foo(); // strictly type-checked function call
+    }
+}
+
+]]>
+  </programlisting>
+  <programlisting role="php">
+<![CDATA[
+<?php 
+declare(strict_types=1); // file 1
+
+/*
+ file 1 - strictly type checked
+ file 2 - weakly type checked
+*/
+
+include 'file2.php';
+
+a(1); // strictly type checked
+b(1); // strictly type checked
+
+function a(int $a) {
+    return $a;
+}
+
+?>
+
+<?php // file 2
+
+b(1); // weakly type checked
+
+function b(int $a) {
+    return $a;
+}
+
+?>
+
+]]>
+  </programlisting>
+  <programlisting role="php">
+<![CDATA[
+<?php // file 1
+
+/*
+ file 1 - weakly type checked
+ file 2 - strictly type checked
+*/
+
+include 'file2.php';
+
+a(1); // weakly type checked
+b(1); // weakly type checked
+
+function a(int $a) {
+    return $a;
+}
+
+
+?>
+
+<?php // file 2
+declare(strict_types=1);
+
+b(1); // strictly type checked
+
+function b(int $a) {
+    return $a;
+}
+
+?>
+
+]]>
+      </programlisting>
+     </example>
+    </para>
+
+
+    <sect3>
+      <para>
+        <example>
+          <title>Type Widening</title>
+          <programlisting role="php">
+<![CDATA[
+<?php 
+declare(strict_types=1);
+
+function a(float $a) {    
+    var_dump($a); // float(1)
+}
+
+$a = 1; // int(1)
+var_dump($a);    
+a($a); 
+
+]]>
+          </programlisting>
+        </example>
+      </para>
+    </sect3>
+   </sect2>
    <sect2 xml:id="functions.variable-arg-list">
     <title>Variable-length argument lists</title>