printf

parse_str

Last updated: Fri, 18 Jul 2008

print

(PHP 4, PHP 5)

print — Visualizza una stringa

Descrizione

int print ( string $arg )

Visualizza arg . Restituisce sempre 1,

In realtà print() non è una funzione (è un costrutto del linguaggio) pertanto non sono richieste le parentesi per la lista degli argomenti.

Example #1 Esempio di uso di print()


<?php
print("Hello World");

print "print() also works without parentheses.";

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

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

print "escaping characters is done \"Like this\".";

// Si possono usare variabili all'interno di istruzioni print
$foo = "foobar";
$bar = "barbaz";

print "foo is $foo"; // foo is foobar

// Si possono usare le matrici
$bar = array("value" => "foo");

print "this is {$bar['value']} !"; // this is foo !

// Utilizzando l'apice singolo sarà visualizzato il nome della variabile e non il contenuto
print 'foo is $foo'; // foo is $foo

// Se non si usa altri caratteri, si può semplicemente visualizzare il contenuto della variabile
print $foo;          // foobar

print <<<END
This uses the "here document" syntax to output
multiple lines with $variable interpolation. Note
that the here document terminator must appear on a
line with just a semicolon no extra whitespace!
END;
?>

Per breve discussione tra print() e echo(), vedere la pagina di FAQTs Knowledge Base Article: » http://www.faqts.com/knowledge_base/view.phtml/aid/1/fid/40

Nota: Poichè questo è un costrutto del linguaggio e non una funzione, non può essere chiamato con le variabili funzione

Vedere anche echo(), printf(), e flush().

printf

parse_str

Last updated: Fri, 18 Jul 2008

add a note User Contributed Notes
print

http://www.danielxmorris.com
28-Aug-2008 07:46


An update to the println function I wrote below, this is a more efficient, correct and returns a value (1, always; (print)).



<?php



    function println($string_message = '') {

        return isset($_SERVER['SERVER_PROTOCOL']) ? print "$string_message<br />" . PHP_EOL:

          print $string_message . PHP_EOL;

    }



?>

user at example dot net
25-Aug-2008 09:47


Be careful when using print. Since print is a language construct and not a function, the parentheses around the argument is not required.

In fact, using parentheses can cause confusion with the syntax of a function and SHOULD be omited.



Most would expect the following behavior:

<?php

    if (print("foo") && print("bar")) {

        // "foo" and "bar" have been printed

    }

?>



But since the parenthesis around the argument are not required, they are interpretet as part of the argument.

This means that the argument of the first print is



    ("foo") && print("bar")



and the argument of the second print is just



    ("bar")



For the expected behavior of the first example, you need to write: 

<?php

    if ((print "foo") && (print "bar")) {

        // "foo" and "bar" have been printed

    }

?>

user at example dot net
25-Aug-2008 09:45


Be careful when using print. Since print is a language construct and not a function, the parentheses around the argument is not required.

In fact, using parentheses can cause confusion with the syntax of a function and SHOULD be omited.



Most would expect the following behavior:

<?php

    if (print("foo") && print("bar")) {

        // "foo" and "bar" had been printed

    }

?>



But since the parenthesis around the argument are not required, they are interpretet as part of the argument.

This means that the argument of the first print is



    ("foo") && print("bar")



and the argument of the second print is just



    ("bar")



For the expected behavior of the first example, you need to write: 

<?php

    if ((print "foo") && (print "bar")) {

        // "foo" and "bar" had been printed

    }

?>

danielxmorris @ gmail dotcom
16-May-2008 04:08


I wrote a println function that determines whether a \n or a <br /> should be appended to the line depending on whether it's being executed in a shell or a browser window.  People have probably thought of this before but I thought I'd post it anyway - it may help a couple of people.



<?php

function println ($string_message) {

    $_SERVER['SERVER_PROTOCOL'] ? print "$string_message<br />" : print "$string_message\n";

}

?>



Examples:



Running in a browser:



<?php println ("Hello, world!"); ?>

Output: Hello, world!<br />



Running in a shell:



<?php println ("Hello, world!"); ?>

Output: Hello, world!\n

jon
01-Jun-2007 07:19


the FAQTs article can be found archived at http://web.archive.org/web/20060601063513/http

://www.faqts.com/knowledge_base/view.phtml/aid/1/fid/40



(url split to get past the line-length limitation)

mvpetrovich
30-Mar-2007 12:02


I grew quite tired of backslashes, and wrote these routines. It uses the back single quote as a substitute for double quotes within a statement.  It made my code much more readable.  It is a little easier than using a "here document."  I also found I make a few less typing errors.



<?php



function qq($text) {return str_replace('`','"',$text); }

function printq($text) { print qq($text); }

function printqn($text) { print qq($text)."\n"; }



//example - before



echo "<a href=\"#\" class=\"stdbutton\" style=\"float:left;\" onclick=\"myfunction(); return false;\">My Link</a>\n";



//becomes - with printqn function



printqn("<a href=`#` class=`stdbutton` style=`float:left;` onclick=`myfunction(); return false;`>My Link</a>");



?>

floppie at quadra-tec dot net
15-Nov-2006 09:09


At the top of your page, do something to this effect:

<?php

    $n = "\n";

    $t = "\t";

?>



Then, if you need your table cell four tabs in:



<?php echo($t . $t . $t . $t . '<td>whatever</td>' . $n); ?>



This means the parser only has to interpret four characters inside double quotes, then just stores them in variables.  With strings that small, concatenating six things together won't be slow at all.

vincent at bevort dot com
21-May-2006 12:36


Sometime there is no choice in using a single or double quote

ie when using special chars to format the output to make the HTML more readable you have to use the Double qoutes. Single quotes make PHP fotmat the '\n' as text

phpnet at i3x171um dot com
20-May-2006 07:41


I have written a script to benchmark the several methods of outputting data in PHP: via single quotes, double quotes, heredoc, and printf. The script constructs a paragraph of text with each method. It performs this construction 10,000 times, then records how long it took. In total, it prints 160,000 times and records 16 timings. Here are the raw results.



Outputted straight to browser--



Single quotes: 2,813 ms

...with concatenation: 1,179 ms

Double quotes: 5,180 ms

...with concatenation: 3,937 ms

heredoc: 7,300 ms

...with concatenation: 6,288 ms

printf: 9,527 ms

...with concatenation: 8,564 ms



Outputted to the output buffer--



Single quotes: 8 ms

...with concatenation: 38 ms

Double quotes: 8 ms

...with concatenation: 47 ms

heredoc: 17 ms

...with concatenation: 49 ms

printf: 54 ms

...with concatenation: 52 ms



A nice graph of the script's output can be found here:

http://i3x171um.com/output_benchmarks/ob.gif



So what should you choose to print your text? I found several things out writing this.



First, it should be noted that the print and echo keywords are interchangeable, performance-wise. The timings show that one is probably an alias for the other. So use whichever you feel most comfortable with.



Second, if you've ever wondered which was better, the definitive answer is single quotes. Single quotes are at least four times faster in any situation. Double quotes, while more convenient, do pose a debatably significant performance issue when outputting massive amounts of data.



Third, stay away from heredoc, and absolutely stay away from [s]printf. They're slow, and the alternatives are there.



The source of my script can be found here:

http://i3x171um.com/output_benchmarks/ob.txt



DO NOT RUN THE SCRIPT ON THE INTERNET! Run it instead from localhost. The script outputs ~45 megabytes of text in an html comment at the top of the page by default. Expect the benchmark to take ~45 seconds. If this is too long, you can change the amount of iterations to a lower number (the results scale accurately down to about 1,000 iterations).

g8z at yahoo dot com
13-Mar-2006 11:16


I wanted to print a file on a Windows 2003 server from PHP, and found the "print" function instead. Just in case some other users are trying to physically print to a printer, rather than print to the screen, here's a function to do it.



This function will print a single file of one of these types: pdf, doc, xls, rtf, or plain text. If you have the full .exe path, you can print other document types, too. The shell_exec function is not enabled in safe mode.



Courtesy of Darren's Script Archive: http://www.tufat.com



<?php



function print_file($filename)

{

    // path to your adobe executable

    $adobe_path='"C:/Program Files/Adobe/Acrobat 7.0/Reader/AcroRd32.exe"';



    $ext='';

    $ext=strrchr($filename,'.');

    $ext=substr($ext,1);

    $ext_xl=substr($ext,0,2);



    if ($ext=='pdf') {

        shell_exec ($adobe_path.' /t '.$filename);

    }

    else if ($ext=='doc'||$ext=='rtf'||$ext=='txt') {

        $word = new COM("Word.Application");

        $word->visible = true;

        $word->Documents->Open($filename);

        $word->ActiveDocument->PrintOut();

        $word->ActiveDocument->Close();

        $word->Quit();

    }

    else if ($ext_xl=='xl') {

        $excel = new COM("Excel.Application");

        $excel->visible = true;

        $excel->Workbooks->Open($filename);

        $excel->ActiveWorkBook->PrintOut();

        $excel->ActiveWorkBook->Close();

        $excel->Quit();

    }

}



// example of printing a PDF



print_file("C:/photo_gallery.pdf");



?>

jon at tap dot net
05-Dec-2005 01:48


I have a small utility run from the command line that processes a potentially huge list of files. As it can take hours to complete, I stuck a  



print '.';



statement in the body of the main loop to prove that something was  happening.



For reasons unknown to me, the utiliity suddenly started buffering the output such that it printed nothing until completion, defeating the purpose of the running monitor. Adding flush() statements did nothing. The problem was solved by using



fputs(STDOUT, '.');



but I have no idea why.

james-web at and dot org
25-Jul-2005 03:47


Note that if you want to dump the value of a variable, you want to use print_r(), var_dump() or var_export().

ejallison at gmail dot com
16-Jul-2005 03:10


This is a simple function for printing debug comments that I didn't think of for a long time. Maybe it'll serve you good too.



<?php



function printd($str) {

  if ($debug) { echo $str; }

}



// ...



if ($valueCalculatedEarlierInTheScript == 3) {

  doSomethingWithNoOutput();

  printd("doSomethingWithNoOutput() has executed.");

}



?>



It's mostly just to make sure everything is running without having to go through everything and put in echo "Step #whatever has executed" whenever something mysterious isn't working.

gem at rellim dot com
05-Nov-2004 01:28


HERE Documents can reference arrays as long as you enclose


the vars in {}.





Like this:





<?php





$line = array( 'title' => "Hello", 'date' => 'Today');





echo <<<EOT


Title: {$line['title']}


Date: {$line['date']}


EOT;





?>





Run this and get


Title: Hello


Date: Today





More info here, scroll down to "heredoc syntax":


http://www.php.net/manual/en/language.types.string.php

rjl at xs4all dot nl
15-Jan-2004 04:08


To elaborate on above example adding an


array variable


$text = <<<END


This uses the "here document" syntax to output


multiple lines with $variable interpolation. Note


that the here document terminator must appear on a


line with just a semicolon no extra whitespace!


User = {$_REQUEST['user']}


END;





'print $text;' Will output the string. Very handy for storing HTML.


Or adding {} around the array will allow you to use


above mentioned html blocks in conjuction with forms.





Rene =<>=

add a note

printf

parse_str

Last updated: Fri, 18 Jul 2008