From 5486657cd95d764253b335c26b201c3693772704 Mon Sep 17 00:00:00 2001
From: Pasindu De Silva <pasindu@php.net>
Date: Sat, 4 Jul 2015 23:18:07 +0000
Subject: [PATCH] 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 | 172 +++++++++++++++++++++++++++++++++++++++--
1 file changed, 166 insertions(+), 6 deletions(-)
diff --git a/language/functions.xml b/language/functions.xml
index 4277add82b..8ca45c8808 100644
--- a/language/functions.xml
+++ b/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>