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<title>Backward incompatible changes</title>
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</div><hr /><div id="migration72.incompatible" class="sect1">
<h2 class="title">Backward incompatible changes</h2>
<div class="sect2" id="migration72.incompatible.number_format-no-neg-zero">
<h3 class="title">Prevent <span class="function"><a href="function.number-format.html" class="function">number_format()</a></span> from returning negative zero</h3>
<p class="para">
Previously, it was possible for the <span class="function"><a href="function.number-format.html" class="function">number_format()</a></span>
function to return <em>-0</em>. Whilst this is perfectly valid
according to the IEEE 754 floating point specification, this oddity was not
desirable for displaying formatted numbers in a human-readable form.
</p>
<div class="informalexample">
<div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB"><?php<br /><br />var_dump</span><span style="color: #007700">(</span><span style="color: #0000BB">number_format</span><span style="color: #007700">(-</span><span style="color: #0000BB">0.01</span><span style="color: #007700">)); </span><span style="color: #FF8000">// now outputs string(1) "0" instead of string(2) "-0"</span>
</span>
</code></div>
</div>
</div>
</div>
<div class="sect2" id="migration72.incompatible.object-array-casts">
<h3 class="title">Convert numeric keys in object and array casts</h3>
<p class="para">
Numeric keys are now better handled when casting arrays to objects and
objects to arrays (either from explicit casting or by
<span class="function"><a href="function.settype.html" class="function">settype()</a></span>).
</p>
<p class="para">
This means that integer (or stringy integer) keys from arrays being casted
to objects are now accessible:
</p>
<div class="informalexample">
<div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB"><?php<br /><br /></span><span style="color: #FF8000">// array to object<br /></span><span style="color: #0000BB">$arr </span><span style="color: #007700">= [</span><span style="color: #0000BB">0 </span><span style="color: #007700">=> </span><span style="color: #0000BB">1</span><span style="color: #007700">];<br /></span><span style="color: #0000BB">$obj </span><span style="color: #007700">= (object)</span><span style="color: #0000BB">$arr</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">var_dump</span><span style="color: #007700">(<br /> </span><span style="color: #0000BB">$obj</span><span style="color: #007700">,<br /> </span><span style="color: #0000BB">$obj</span><span style="color: #007700">->{</span><span style="color: #DD0000">'0'</span><span style="color: #007700">}, </span><span style="color: #FF8000">// now accessible<br /> </span><span style="color: #0000BB">$obj</span><span style="color: #007700">->{</span><span style="color: #0000BB">0</span><span style="color: #007700">} </span><span style="color: #FF8000">// now accessible<br /></span><span style="color: #007700">);</span>
</span>
</code></div>
</div>
<p class="para">The above example will output:</p>
<div class="example-contents screen">
<div class="cdata"><pre>
object(stdClass)#1 (1) {
["0"]=> // string key now, rather than integer key
int(1)
}
int(1)
int(1)
</pre></div>
</div>
</div>
<p class="para">
And integer (or stringy integer) keys from objects being casted to arrays
are now accessible:
</p>
<div class="informalexample">
<div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB"><?php<br /><br /></span><span style="color: #FF8000">// object to array<br /></span><span style="color: #0000BB">$obj </span><span style="color: #007700">= new class {<br /> public function </span><span style="color: #0000BB">__construct</span><span style="color: #007700">()<br /> {<br /> </span><span style="color: #0000BB">$this</span><span style="color: #007700">->{</span><span style="color: #0000BB">0</span><span style="color: #007700">} = </span><span style="color: #0000BB">1</span><span style="color: #007700">;<br /> }<br />};<br /></span><span style="color: #0000BB">$arr </span><span style="color: #007700">= (array)</span><span style="color: #0000BB">$obj</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">var_dump</span><span style="color: #007700">(<br /> </span><span style="color: #0000BB">$arr</span><span style="color: #007700">,<br /> </span><span style="color: #0000BB">$arr</span><span style="color: #007700">[</span><span style="color: #0000BB">0</span><span style="color: #007700">], </span><span style="color: #FF8000">// now accessible<br /> </span><span style="color: #0000BB">$arr</span><span style="color: #007700">[</span><span style="color: #DD0000">'0'</span><span style="color: #007700">] </span><span style="color: #FF8000">// now accessible<br /></span><span style="color: #007700">);</span>
</span>
</code></div>
</div>
<p class="para">The above example will output:</p>
<div class="example-contents screen">
<div class="cdata"><pre>
array(1) {
[0]=> // integer key now, rather than string key
int(1)
}
int(1)
int(1)
</pre></div>
</div>
</div>
</div>
<div class="sect2" id="migration72.incompatible.no-null-to-get_class">
<h3 class="title">Disallow passing <strong><code>NULL</code></strong> to <span class="function"><a href="function.get-class.html" class="function">get_class()</a></span></h3>
<p class="para">
Previously, passing <strong><code>NULL</code></strong> to the <span class="function"><a href="function.get-class.html" class="function">get_class()</a></span> function
would output the name of the enclosing class. This behaviour has now been
removed, where an <strong><code>E_WARNING</code></strong> will be output instead. To
achieve the same behaviour as before, the argument should simply be omitted.
</p>
</div>
<div class="sect2" id="migration72.incompatible.warn-on-non-countable-types">
<h3 class="title">Warn when counting non-countable types</h3>
<p class="para">
An <strong><code>E_WARNING</code></strong> will now be emitted when attempting to
<span class="function"><a href="function.count.html" class="function">count()</a></span> non-countable types (this includes the
<span class="function"><a href="function.sizeof.html" class="function">sizeof()</a></span> alias function).
</p>
<div class="informalexample">
<div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB"><?php<br /><br />var_dump</span><span style="color: #007700">(<br /> </span><span style="color: #0000BB">count</span><span style="color: #007700">(</span><span style="color: #0000BB">null</span><span style="color: #007700">), </span><span style="color: #FF8000">// NULL is not countable<br /> </span><span style="color: #0000BB">count</span><span style="color: #007700">(</span><span style="color: #0000BB">1</span><span style="color: #007700">), </span><span style="color: #FF8000">// integers are not countable<br /> </span><span style="color: #0000BB">count</span><span style="color: #007700">(</span><span style="color: #DD0000">'abc'</span><span style="color: #007700">), </span><span style="color: #FF8000">// strings are not countable<br /> </span><span style="color: #0000BB">count</span><span style="color: #007700">(new </span><span style="color: #0000BB">stdclass</span><span style="color: #007700">), </span><span style="color: #FF8000">// objects not implementing the Countable interface are not countable<br /> </span><span style="color: #0000BB">count</span><span style="color: #007700">([</span><span style="color: #0000BB">1</span><span style="color: #007700">,</span><span style="color: #0000BB">2</span><span style="color: #007700">]) </span><span style="color: #FF8000">// arrays are countable<br /></span><span style="color: #007700">);</span>
</span>
</code></div>
</div>
<p class="para">The above example will output:</p>
<div class="example-contents screen">
<div class="cdata"><pre>
Warning: count(): Parameter must be an array or an object that implements Countable in %s on line %d
Warning: count(): Parameter must be an array or an object that implements Countable in %s on line %d
Warning: count(): Parameter must be an array or an object that implements Countable in %s on line %d
Warning: count(): Parameter must be an array or an object that implements Countable in %s on line %d
int(0)
int(1)
int(1)
int(1)
int(2)
</pre></div>
</div>
</div>
</div>
<div class="sect2" id="migration72.incompatible.hash-ext-to-objects">
<h3 class="title">Move ext/hash from resources to objects</h3>
<p class="para">
As part of the long-term migration away from resources, the <a href="book.hash.html" class="link">Hash</a>
extension has been updated to use objects instead of resources. The change should be
seamless for PHP developers, except for where
<span class="function"><a href="function.is-resource.html" class="function">is_resource()</a></span> checks have been made (which will need
updating to <span class="function"><a href="function.is-object.html" class="function">is_object()</a></span> instead).
</p>
</div>
<div class="sect2" id="migration72.incompatible.ssl-tls-defaults">
<h3 class="title">Improve SSL/TLS defaults</h3>
<p class="para">
The following changes to the defaults have been made:
</p>
<ul class="itemizedlist">
<li class="listitem">
<span class="simpara">
<em>tls://</em> now defaults to TLSv1.0 or TLSv1.1 or TLSv1.2
</span>
</li>
<li class="listitem">
<span class="simpara">
<em>ssl://</em> an alias of <em>tls://</em>
</span>
</li>
<li class="listitem">
<span class="simpara">
<em>STREAM_CRYPTO_METHOD_TLS_*</em> constants default to TLSv1.0
or TLSv1.1 + TLSv1.2, instead of TLSv1.0 only
</span>
</li>
</ul>
</div>
<div class="sect2" id="migration72.incompatible.gettype-on-closed-resource">
<h3 class="title"><span class="function"><a href="function.gettype.html" class="function">gettype()</a></span> return value on closed resources</h3>
<p class="para">
Previously, using <span class="function"><a href="function.gettype.html" class="function">gettype()</a></span> on a closed resource would
return a string of <em>"unknown type"</em>. Now, a string of
<em>"resource (closed)"</em> will be returned.
</p>
</div>
<div class="sect2" id="migration72.incompatible.is_object-on-incomplete_class">
<h3 class="title"><span class="function"><a href="function.is-object.html" class="function">is_object()</a></span> and <strong class="classname">__PHP_Incomplete_Class</strong></h3>
<p class="para">
Previously, using <span class="function"><a href="function.is-object.html" class="function">is_object()</a></span> on the
<strong class="classname">__PHP_Incomplete_Class</strong> class would return <strong><code>FALSE</code></strong>.
Now, <strong><code>TRUE</code></strong> will be returned.
</p>
</div>
<div class="sect2" id="migration72.incompatible.undefined-constants">
<h3 class="title">Promote the error level of undefined constants</h3>
<p class="para">
Unqualified references to undefined constants will now generate an
<strong><code>E_WARNING</code></strong> (instead of an <strong><code>E_NOTICE</code></strong>).
In the next major version of PHP, they will generate
<a href="class.error.html" class="classname">Error</a> exceptions.
</p>
</div>
<div class="sect2" id="migration72.incompatible.windows-support">
<h3 class="title">Windows support</h3>
<p class="para">
The officially supported, minimum Windows versions are now Windows 7/Server
2008 R2.
</p>
</div>
<div class="sect2" id="migration72.incompatible.trait-properties">
<h3 class="title">Checks on default property values of traits</h3>
<p class="para">
Compatibility checks upon default trait property values will no longer
perform casting.
</p>
</div>
<div class="sect2" id="migration72.incompatible.object-reserved-word">
<h3 class="title"><em>object</em> for class names</h3>
<p class="para">
The <em>object</em> name was previously soft-reserved in PHP 7.0.
This is now hard-reserved, prohibiting it from being used as a class, trait,
or interface name.
</p>
</div>
<div class="sect2" id="migration72.incompatible.netware-support">
<h3 class="title">NetWare support</h3>
<p class="para">
Support for NetWare has now been removed.
</p>
</div>
<div class="sect2" id="migration72.incompatible.array-unique">
<h3 class="title"><span class="function"><a href="function.array-unique.html" class="function">array_unique()</a></span> with <strong><code>SORT_STRING</code></strong></h3>
<p class="para">
While <span class="function"><a href="function.array-unique.html" class="function">array_unique()</a></span> with <strong><code>SORT_STRING</code></strong>
formerly copied the array and removed non-unique elements (without packing
the array afterwards), now a new array is built by adding the
unique elements. This can result in different numeric indexes.
</p>
</div>
<div class="sect2" id="migration72.incompatible.bcmod-and-floats">
<h3 class="title"><span class="function"><a href="function.bcmod.html" class="function">bcmod()</a></span> changes with floats</h3>
<p class="para">
The <span class="function"><a href="function.bcmod.html" class="function">bcmod()</a></span> function no longer truncates fractional
numbers to integers. As such, its behavior now follows
<span class="function"><a href="function.fmod.html" class="function">fmod()</a></span>, rather than the <em>%</em> operator.
For example <em>bcmod('4', '3.5')</em> now returns
<em>0.5</em> instead of <em>1</em>.
</p>
</div>
<div class="sect2" id="migration72.incompatible.hash-functions">
<h3 class="title">Hashing functions and non-cryptographic hashes</h3>
<p class="para">
The <span class="function"><a href="function.hash-hmac.html" class="function">hash_hmac()</a></span>, <span class="function"><a href="function.hash-hmac-file.html" class="function">hash_hmac_file()</a></span>,
<span class="function"><a href="function.hash-pbkdf2.html" class="function">hash_pbkdf2()</a></span>, and <span class="function"><a href="function.hash-init.html" class="function">hash_init()</a></span> (with
<strong><code>HASH_HMAC</code></strong>) functions no longer accept non-cryptographic
hashes.
</p>
</div>
<div class="sect2" id="migration72.incompatible.json_decode-changes">
<h3 class="title"><span class="function"><a href="function.json-decode.html" class="function">json_decode()</a></span> function options</h3>
<p class="para">
The <span class="function"><a href="function.json-decode.html" class="function">json_decode()</a></span> function option,
<strong><code>JSON_OBJECT_AS_ARRAY</code></strong>, is now used if the second
parameter (assoc) is <strong><code>NULL</code></strong>. Previously,
<strong><code>JSON_OBJECT_AS_ARRAY</code></strong> was always ignored.
</p>
</div>
<div class="sect2" id="migration72.incompatible.rand-mt_rand-output">
<h3 class="title"><span class="function"><a href="function.rand.html" class="function">rand()</a></span> and <span class="function"><a href="function.mt-rand.html" class="function">mt_rand()</a></span> output</h3>
<p class="para">
Sequences generated by <span class="function"><a href="function.rand.html" class="function">rand()</a></span> and
<span class="function"><a href="function.mt-rand.html" class="function">mt_rand()</a></span> for a specific seed may differ from PHP 7.1 on
64-bit machines (due to the fixing of a modulo bias bug in the
implementation).
</p>
</div>
<div class="sect2" id="migration72.incompatible.sqlsafe_mode-ini-setting">
<h3 class="title">Removal of <a href="ini.core.html#ini.sql.safe-mode" class="link"><code class="parameter">sql.safe_mode</code></a> ini setting</h3>
<p class="para">
The <code class="parameter">sql.safe_mode</code> ini setting has now been removed.
</p>
</div>
<div class="sect2" id="migration72.incompatible.date_parse_from_format">
<h3 class="title">Changes to <span class="function"><a href="function.date-parse-from-format.html" class="function">date_parse_from_format()</a></span></h3>
<p class="para">
The <em>zone</em> element of the array returned by
<span class="function"><a href="function.date-parse-from-format.html" class="function">date_parse_from_format()</a></span> represents seconds instead of
minutes now, and its sign is inverted. For instance <em>-120</em>
is now <em>7200</em>.
</p>
</div>
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