php-doc-en/reference/strings/functions/print.xml

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<refentry xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://docbook.org/ns/docbook" xml:id="function.print">
 <refnamediv>
  <refname>print</refname>
  <refpurpose>Output a string</refpurpose>
 </refnamediv>
 
 <refsect1 role="description">
  &reftitle.description;
  <methodsynopsis>
   <type>int</type><methodname>print</methodname>
   <methodparam><type>string</type><parameter>expression</parameter></methodparam>
  </methodsynopsis>
  <para>
   Outputs <parameter>expression</parameter>.
  </para>
  <para>
   <literal>print</literal> is not a function but a language construct.
   Its argument is the expression following the <literal>print</literal> keyword,
   and is not delimited by parentheses.
  </para>
  <para>
   The major differences to <function>echo</function> are that
   <literal>print</literal> only accepts a single argument and always returns
   <literal>1</literal>.
  </para>
 </refsect1>

 <refsect1 role="parameters">
  &reftitle.parameters;
  <para>
   <variablelist>
    <varlistentry>
     <term><parameter>expression</parameter></term>
     <listitem>
      <para>
       The expression to be output. Non-string values will be coerced to strings,
       even when <link linkend="language.types.declarations.strict">the
       <literal>strict_types</literal> directive</link> is enabled.
      </para>
     </listitem>
    </varlistentry>
   </variablelist>
  </para>
 </refsect1>

 <refsect1 role="returnvalues">
  &reftitle.returnvalues;
  <para>
   Returns <literal>1</literal>, always.
  </para>
 </refsect1>

 <refsect1 role="examples">
  &reftitle.examples;
  <para>
   <example>
    <title><literal>print</literal> examples</title>
    <programlisting role="php">
<![CDATA[
<?php
print "print does not require parentheses.";

// No newline or space is added; the below outputs "helloworld" all on one line
print "hello";
print "world";

print "This string spans
multiple lines. The newlines will be
output as well";

print "This string spans\nmultiple lines. The newlines will be\noutput as well.";

// The argument can be any expression which produces a string
$foo = "example";
print "foo is $foo"; // foo is example

$fruits = ["lemon", "orange", "banana"];
print implode(" and ", $fruits); // lemon and orange and banana

// Non-string expressions are coerced to string, even if declare(strict_types=1) is used
print 6 * 7; // 42

// Because print has a return value, it can be used in expressions
// The following outputs "hello world"
if ( print "hello" ) {
    echo " world";
}

// The following outputs "true"
( 1 === 1 ) ? print 'true' : print 'false';
?>
]]>
    </programlisting>
   </example>
  </para>
 </refsect1>

 <refsect1 role="notes">
  &reftitle.notes;

  <note>
   <title>Using with parentheses</title>
   <para>
    Surrounding the argument to <literal>print</literal> with parentheses will not
    raise a syntax error, and produces syntax which looks like a normal
    function call. However, this can be misleading, because the parentheses are actually
    part of the expression being output, not part of the <literal>print</literal>
    syntax itself.
   </para>
   <para>
    <example>
     <title/>
     <programlisting role="php">
<![CDATA[
<?php
print "hello";
// outputs "hello"

print("hello");
// also outputs "hello", because ("hello") is a valid expression

print(1 + 2) * 3;
// outputs "9"; the parentheses cause 1+2 to be evaluated first, then 3*3
// the print statement sees the whole expression as one argument

if ( print("hello") && false ) {
    print " - inside if";
}
else {
    print " - inside else";
}
// outputs " - inside if"
// the expression ("hello") && false is first evaluated, giving false
// this is coerced to the empty string "" and printed
// the print construct then returns 1, so code in the if block is run
?>
]]>
     </programlisting>
    </example>
   </para>

   <para>
    When using <literal>print</literal> in a larger expression, placing both the
    keyword and its argument in parentheses may be necessary to give the intended
    result:
   </para>

   <para>
    <example>
     <title/>
     <programlisting role="php">
<![CDATA[
<?php
if ( (print "hello") && false ) {
    print " - inside if";
}
else {
    print " - inside else";
}
// outputs "hello - inside else"
// unlike the previous example, the expression (print "hello") is evaluated first
// after outputting "hello", print returns 1
// since 1 && false is false, code in the else block is run

print "hello " && print "world";
// outputs "world1"; print "world" is evaluated first,
// then the expression "hello " && 1 is passed to the left-hand print

(print "hello ") && (print "world");
// outputs "hello world"; the parentheses force the print expressions
// to be evaluated before the &&
?>
]]>
     </programlisting>
    </example>
   </para>
  </note>

  &note.language-construct;
 </refsect1>

 <refsect1 role="seealso">
  &reftitle.seealso;
  <para>
   <simplelist>
    <member><function>echo</function></member>
    <member><function>printf</function></member>
    <member><function>flush</function></member>
    <member><link linkend="language.types.string">Ways to specify literal strings</link></member>
   </simplelist>
  </para>
 </refsect1>

</refentry>

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