mirror of
https://github.com/sigmasternchen/php-doc-en
synced 2025-03-19 02:18:56 +00:00
b7cc7c99e0
git-svn-id: https://svn.php.net/repository/phpdoc/en/trunk@12658 c90b9560-bf6c-de11-be94-00142212c4b1
535 lines
14 KiB
Text
535 lines
14 KiB
Text
<reference id="ref.var">
|
|
<title>Variable functions</title>
|
|
<titleabbrev>Variables</titleabbrev>
|
|
|
|
<refentry id="function.doubleval">
|
|
<refnamediv>
|
|
<refname>doubleval</refname>
|
|
<refpurpose>Get double value of a variable.</refpurpose>
|
|
</refnamediv>
|
|
<refsect1>
|
|
<title>Description</title>
|
|
<funcsynopsis>
|
|
<funcdef>double <function>doubleval</function></funcdef>
|
|
<paramdef>mixed <parameter>var</parameter></paramdef>
|
|
</funcsynopsis>
|
|
|
|
<simpara>
|
|
Returns the double (floating point) value of <parameter>var</parameter>.
|
|
|
|
<simpara>
|
|
<parameter>var</parameter> may be any scalar type. You cannot use
|
|
<function>doubleval</function> on arrays or objects.
|
|
|
|
<simpara>
|
|
See also <function>intval</function>,
|
|
<function>strval</function>,
|
|
<function>settype</function> and <link
|
|
linkend="language.types.type-juggling">Type juggling</link>.
|
|
|
|
</refsect1>
|
|
</refentry>
|
|
|
|
|
|
<refentry id="function.empty">
|
|
<refnamediv>
|
|
<refname>empty</refname>
|
|
<refpurpose>determine whether a variable is set</refpurpose>
|
|
</refnamediv>
|
|
<refsect1>
|
|
<title>Description</title>
|
|
<funcsynopsis>
|
|
<funcdef>int <function>empty</function></funcdef>
|
|
<paramdef>mixed <parameter>var</parameter></paramdef>
|
|
</funcsynopsis>
|
|
|
|
<simpara>
|
|
Returns false if <parameter>var</parameter> is set and has a
|
|
non-empty or non-zero value; true otherwise.
|
|
|
|
<simpara>
|
|
See also <function>isset</function> and <function>unset</function>.
|
|
|
|
</refsect1>
|
|
</refentry>
|
|
|
|
|
|
<refentry id="function.gettype">
|
|
<refnamediv>
|
|
<refname>gettype</refname>
|
|
<refpurpose>Get the type of a variable.</refpurpose>
|
|
</refnamediv>
|
|
<refsect1>
|
|
<title>Description</title>
|
|
<funcsynopsis>
|
|
<funcdef>string <function>gettype</function></funcdef>
|
|
<paramdef>mixed <parameter>var</parameter></paramdef>
|
|
</funcsynopsis>
|
|
|
|
<para>
|
|
Returns the type of the PHP variable <parameter>var</parameter>.
|
|
|
|
<para>
|
|
Possibles values for the returned string are:
|
|
<itemizedlist>
|
|
<listitem><simpara>"integer"
|
|
<listitem><simpara>"double"
|
|
<listitem><simpara>"string"
|
|
<listitem><simpara>"array"
|
|
<listitem><simpara>"object"
|
|
<listitem><simpara>"unknown type"
|
|
</itemizedlist>
|
|
|
|
<para>
|
|
See also <function>settype</function>.
|
|
|
|
</refsect1>
|
|
</refentry>
|
|
|
|
|
|
<refentry id="function.intval">
|
|
<refnamediv>
|
|
<refname>intval</refname>
|
|
<refpurpose>Get integer value of a variable.</refpurpose>
|
|
</refnamediv>
|
|
<refsect1>
|
|
<title>Description</title>
|
|
<funcsynopsis>
|
|
<funcdef>int <function>intval</function></funcdef>
|
|
<paramdef>mixed <parameter>var</parameter></paramdef>
|
|
<paramdef>int <parameter><optional>base</optional></parameter></paramdef>
|
|
</funcsynopsis>
|
|
|
|
<simpara>
|
|
Returns the integer value of <parameter>var</parameter>,
|
|
using the specified base for the conversion (the default is
|
|
base 10).
|
|
|
|
<simpara>
|
|
<parameter>var</parameter> may be any scalar type. You cannot use
|
|
<function>intval</function> on arrays or objects.
|
|
|
|
<simpara>
|
|
See also <function>doubleval</function>,
|
|
<function>strval</function>,
|
|
<function>settype</function> and <link
|
|
linkend="language.types.type-juggling">Type juggling</link>.
|
|
|
|
</refsect1>
|
|
</refentry>
|
|
|
|
<refentry id="function.is-array">
|
|
<refnamediv>
|
|
<refname>is_array</refname>
|
|
<refpurpose>Finds whether a variable is an array.</refpurpose>
|
|
</refnamediv>
|
|
<refsect1>
|
|
<title>Description</title>
|
|
<funcsynopsis>
|
|
<funcdef>int <function>is_array</function></funcdef>
|
|
<paramdef>mixed <parameter>var</parameter></paramdef>
|
|
</funcsynopsis>
|
|
|
|
<para>
|
|
Returns true if <parameter>var</parameter> is an array, false
|
|
otherwise.
|
|
|
|
<para>
|
|
See also <function>is_double</function>,
|
|
<function>is_float</function>,
|
|
<function>is_int</function>,
|
|
<function>is_integer</function>,
|
|
<function>is_real</function>,
|
|
<function>is_string</function>,
|
|
<function>is_long</function>, and
|
|
<function>is_object</function>.
|
|
|
|
</refsect1>
|
|
</refentry>
|
|
|
|
|
|
<refentry id="function.is-double">
|
|
<refnamediv>
|
|
<refname>is_double</refname>
|
|
<refpurpose>Finds whether a variable is a double.</refpurpose>
|
|
</refnamediv>
|
|
<refsect1>
|
|
<title>Description</title>
|
|
<funcsynopsis>
|
|
<funcdef>int <function>is_double</function></funcdef>
|
|
<paramdef>mixed <parameter>var</parameter></paramdef>
|
|
</funcsynopsis>
|
|
|
|
<para>
|
|
Returns true if <parameter>var</parameter> is a double,
|
|
false otherwise.
|
|
|
|
<para>
|
|
See also <function>is_array</function>,
|
|
<function>is_float</function>,
|
|
<function>is_int</function>,
|
|
<function>is_integer</function>,
|
|
<function>is_real</function>,
|
|
<function>is_string</function>,
|
|
<function>is_long</function>, and
|
|
<function>is_object</function>.
|
|
|
|
</refsect1>
|
|
</refentry>
|
|
|
|
|
|
<refentry id="function.is-float">
|
|
<refnamediv>
|
|
<refname>is_float</refname>
|
|
<refpurpose>Finds whether a variable is a float.</refpurpose>
|
|
</refnamediv>
|
|
<refsect1>
|
|
<title>Description</title>
|
|
<funcsynopsis>
|
|
<funcdef>int <function>is_float</function></funcdef>
|
|
<paramdef>mixed <parameter>var</parameter></paramdef>
|
|
</funcsynopsis>
|
|
|
|
<simpara>
|
|
This function is an alias for <function>is_double</function>.
|
|
|
|
<simpara>
|
|
See also <function>is_double</function>,
|
|
<function>is_real</function>,
|
|
<function>is_int</function>,
|
|
<function>is_integer</function>,
|
|
<function>is_string</function>,
|
|
<function>is_object</function>,
|
|
<function>is_array</function>, and
|
|
<function>is_long</function>.
|
|
|
|
</refsect1>
|
|
</refentry>
|
|
|
|
|
|
<refentry id="function.is-int">
|
|
<refnamediv>
|
|
<refname>is_int</refname>
|
|
<refpurpose>Find whether a variable is an integer.</refpurpose>
|
|
</refnamediv>
|
|
<refsect1>
|
|
<title>Description</title>
|
|
<funcsynopsis>
|
|
<funcdef>int <function>is_int</function></funcdef>
|
|
<paramdef>mixed <parameter>var</parameter></paramdef>
|
|
</funcsynopsis>
|
|
|
|
<simpara>
|
|
This function is an alias for <function>is_long</function>.
|
|
|
|
<simpara>
|
|
See also <function>is_double</function>,
|
|
<function>is_float</function>,
|
|
<function>is_integer</function>,
|
|
<function>is_string</function>,
|
|
<function>is_real</function>,
|
|
<function>is_object</function>,
|
|
<function>is_array</function>, and
|
|
<function>is_long</function>.
|
|
|
|
</refsect1>
|
|
</refentry>
|
|
|
|
|
|
<refentry id="function.is-integer">
|
|
<refnamediv>
|
|
<refname>is_integer</refname>
|
|
<refpurpose>Find whether a variable is an integer.</refpurpose>
|
|
</refnamediv>
|
|
<refsect1>
|
|
<title>Description</title>
|
|
<funcsynopsis>
|
|
<funcdef>int <function>is_integer</function></funcdef>
|
|
<paramdef>mixed <parameter>var</parameter></paramdef>
|
|
</funcsynopsis>
|
|
|
|
<simpara>
|
|
This function is an alias for <function>is_long</function>.
|
|
|
|
<simpara>
|
|
See also <function>is_double</function>,
|
|
<function>is_float</function>,
|
|
<function>is_int</function>,
|
|
<function>is_string</function>,
|
|
<function>is_real</function>,
|
|
<function>is_object</function>,
|
|
<function>is_array</function>, and
|
|
<function>is_long</function>.
|
|
|
|
</refsect1>
|
|
</refentry>
|
|
|
|
|
|
<refentry id="function.is-long">
|
|
<refnamediv>
|
|
<refname>is_long</refname>
|
|
<refpurpose>Finds whether a variable is an integer.</refpurpose>
|
|
</refnamediv>
|
|
<refsect1>
|
|
<title>Description</title>
|
|
<funcsynopsis>
|
|
<funcdef>int <function>is_long</function></funcdef>
|
|
<paramdef>mixed <parameter>var</parameter></paramdef>
|
|
</funcsynopsis>
|
|
|
|
<para>
|
|
Returns true if <parameter>var</parameter> is an integer (long),
|
|
false otherwise.
|
|
|
|
<para>
|
|
See also <function>is_double</function>,
|
|
<function>is_float</function>,
|
|
<function>is_int</function>,
|
|
<function>is_real</function>,
|
|
<function>is_string</function>,
|
|
<function>is_object</function>,
|
|
<function>is_array</function>, and
|
|
<function>is_integer</function>.
|
|
|
|
</refsect1>
|
|
</refentry>
|
|
|
|
|
|
<refentry id="function.is-object">
|
|
<refnamediv>
|
|
<refname>is_object</refname>
|
|
<refpurpose>Finds whether a variable is an object.</refpurpose>
|
|
</refnamediv>
|
|
<refsect1>
|
|
<title>Description</title>
|
|
<funcsynopsis>
|
|
<funcdef>int <function>is_object</function></funcdef>
|
|
<paramdef>mixed <parameter>var</parameter></paramdef>
|
|
</funcsynopsis>
|
|
|
|
<para>
|
|
Returns true if <parameter>var</parameter> is an object, false
|
|
otherwise.
|
|
|
|
<para>
|
|
See also <function>is_long</function>,
|
|
<function>is_int</function>,
|
|
<function>is_integer</function>,
|
|
<function>is_float</function>,
|
|
<function>is_double</function>,
|
|
<function>is_real</function>,
|
|
<function>is_string</function>, and
|
|
<function>is_array</function>.
|
|
|
|
</refsect1>
|
|
</refentry>
|
|
|
|
|
|
<refentry id="function.is-real">
|
|
<refnamediv>
|
|
<refname>is_real</refname>
|
|
<refpurpose>Finds whether a variable is a real.</refpurpose>
|
|
</refnamediv>
|
|
<refsect1>
|
|
<title>Description</title>
|
|
<funcsynopsis>
|
|
<funcdef>int <function>is_real</function></funcdef>
|
|
<paramdef>mixed <parameter>var</parameter></paramdef>
|
|
</funcsynopsis>
|
|
|
|
<simpara>
|
|
This function is an alias for <function>is_double</function>.
|
|
|
|
<simpara>
|
|
See also <function>is_long</function>,
|
|
<function>is_int</function>,
|
|
<function>is_integer</function>,
|
|
<function>is_float</function>,
|
|
<function>is_double</function>,
|
|
<function>is_object</function>,
|
|
<function>is_string</function>, and
|
|
<function>is_array</function>.
|
|
|
|
</refsect1>
|
|
</refentry>
|
|
|
|
|
|
<refentry id="function.is-string">
|
|
<refnamediv>
|
|
<refname>is_string</refname>
|
|
<refpurpose>Finds whether a variable is a string.</refpurpose>
|
|
</refnamediv>
|
|
<refsect1>
|
|
<title>Description</title>
|
|
<funcsynopsis>
|
|
<funcdef>int <function>is_string</function></funcdef>
|
|
<paramdef>mixed <parameter>var</parameter></paramdef>
|
|
</funcsynopsis>
|
|
|
|
<para>
|
|
Returns true if <parameter>var</parameter> is a string,
|
|
false otherwise.
|
|
|
|
<para>
|
|
See also <function>is_long</function>,
|
|
<function>is_int</function>,
|
|
<function>is_integer</function>,
|
|
<function>is_float</function>,
|
|
<function>is_double</function>,
|
|
<function>is_real</function>,
|
|
<function>is_object</function>, and
|
|
<function>is_array</function>.
|
|
|
|
</refsect1>
|
|
</refentry>
|
|
|
|
|
|
<refentry id="function.isset">
|
|
<refnamediv>
|
|
<refname>isset</refname>
|
|
<refpurpose>determine whether a variable is set</refpurpose>
|
|
</refnamediv>
|
|
<refsect1>
|
|
<title>Description</title>
|
|
<funcsynopsis>
|
|
<funcdef>int <function>isset</function></funcdef>
|
|
<paramdef>mixed <parameter>var</parameter></paramdef>
|
|
</funcsynopsis>
|
|
|
|
<simpara>
|
|
Returns true if <parameter>var</parameter> exists;
|
|
false otherwise.
|
|
|
|
<para>
|
|
If a variable has been unset with <function>unset</function>,
|
|
it will no longer be <function>isset</function>.
|
|
<informalexample><programlisting>
|
|
$a = "test";
|
|
echo isset($a); // true
|
|
unset($a);
|
|
echo isset($a); // false
|
|
</programlisting></informalexample>
|
|
|
|
<simpara>
|
|
See also <function>empty</function> and <function>unset</function>.
|
|
|
|
</refsect1>
|
|
</refentry>
|
|
|
|
|
|
<refentry id="function.settype">
|
|
<refnamediv>
|
|
<refname>settype</refname>
|
|
<refpurpose>Set the type of a variable.</refpurpose>
|
|
</refnamediv>
|
|
<refsect1>
|
|
<title>Description</title>
|
|
<funcsynopsis>
|
|
<funcdef>int <function>settype</function></funcdef>
|
|
<paramdef>string <parameter>var</parameter></paramdef>
|
|
<paramdef>string <parameter>type</parameter></paramdef>
|
|
</funcsynopsis>
|
|
|
|
<para>
|
|
Set the type of variable <parameter>var</parameter> to
|
|
<parameter>type</parameter>.
|
|
|
|
<para>
|
|
Possibles values of <parameter>type</parameter> are:
|
|
<itemizedlist>
|
|
<listitem><simpara>"integer"
|
|
<listitem><simpara>"double"
|
|
<listitem><simpara>"string"
|
|
<listitem><simpara>"array"
|
|
<listitem><simpara>"object"
|
|
</itemizedlist>
|
|
|
|
<para>
|
|
Returns true if successful; otherwise returns false.
|
|
|
|
<para>
|
|
See also <function>gettype</function>.
|
|
|
|
</refsect1>
|
|
</refentry>
|
|
|
|
|
|
<refentry id="function.strval">
|
|
<refnamediv>
|
|
<refname>strval</refname>
|
|
<refpurpose>Get string value of a variable.</refpurpose>
|
|
</refnamediv>
|
|
<refsect1>
|
|
<title>Description</title>
|
|
<funcsynopsis>
|
|
<funcdef>string <function>strval</function></funcdef>
|
|
<paramdef>mixed <parameter>var</parameter></paramdef>
|
|
</funcsynopsis>
|
|
|
|
<simpara>
|
|
Returns the string value of <parameter>var</parameter>.
|
|
|
|
<simpara>
|
|
<parameter>var</parameter> may be any scalar type. You cannot use
|
|
<function>strval</function> on arrays or objects.
|
|
|
|
<simpara>
|
|
See also <function>doubleval</function>,
|
|
<function>intval</function>,
|
|
<function>settype</function> and <link
|
|
linkend="language.types.type-juggling">Type juggling</link>.
|
|
|
|
</refsect1>
|
|
</refentry>
|
|
|
|
|
|
<refentry id="function.unset">
|
|
<refnamediv>
|
|
<refname>unset</refname>
|
|
<refpurpose>Unset a given variable</refpurpose>
|
|
</refnamediv>
|
|
<refsect1>
|
|
<title>Description</title>
|
|
<funcsynopsis>
|
|
<funcdef>int <function>unset</function></funcdef>
|
|
<paramdef>mixed <parameter>var</parameter></paramdef>
|
|
</funcsynopsis>
|
|
|
|
<para>
|
|
<function>unset</function> destroys the specified variable and
|
|
returns true.
|
|
|
|
<para>
|
|
<example>
|
|
<title><function>unset</function> example</title>
|
|
<programlisting>
|
|
unset( $foo );
|
|
unset( $bar['quux'] );
|
|
</programlisting>
|
|
</example>
|
|
|
|
<para>
|
|
See also <function>isset</function> and <function>empty</function>.
|
|
|
|
</refsect1>
|
|
</refentry>
|
|
|
|
|
|
</reference>
|
|
|
|
<!-- Keep this comment at the end of the file
|
|
Local variables:
|
|
mode: sgml
|
|
sgml-omittag:t
|
|
sgml-shorttag:t
|
|
sgml-minimize-attributes:nil
|
|
sgml-always-quote-attributes:t
|
|
sgml-indent-step:1
|
|
sgml-indent-data:t
|
|
sgml-parent-document:nil
|
|
sgml-default-dtd-file:"../manual.ced"
|
|
sgml-exposed-tags:nil
|
|
sgml-local-catalogs:nil
|
|
sgml-local-ecat-files:nil
|
|
End:
|
|
-->
|