function as the argument of another function?

fowlerlfc · Sep 17, 2002

I'm using php 4.2.1. Can a function be an argument for another function?

Here's a little test script I've tried:
<?
//test functions
function neato ($content) {
echo "<html><head><title></title></head><body><table><tr><td>$content</td></tr></table></body></html>";
}

function content() {
echo "<table border=\"1\"><tr><td>this is a test</td></tr></table>";
}

//try it by assigning content function to a variable
$test = content();
neato($test);
//or by making it the argument directly
neato(content());
?>

When I test this I always get the output of content() before the output of neato(). When I want the output of content() to be inside the output of neato(). Does this make sense? Is it possible?

Thanks in advance for your help.

sleipnir214 · Sep 17, 2002

That's because content() echos.

If you want the value of what content() produces, you must return it to neato().

http://www.php.net/manual/en/functions.returning-values.php

______________________________________________________________________
TANSTAAFL!

fowlerlfc · Sep 17, 2002

i guess i should rtfm in it's entirety! thanks so much!

sleipnir214 · Sep 17, 2002

Good luck reading PHP's manual in it's entirety.

I think printed out, it's about 1500 pages. ______________________________________________________________________
TANSTAAFL!

RbgoWeb · Sep 17, 2002

What you try to apply is officially called a 'callback' function.
Do it like this in PHP...

function writeTD($td)
{
echo "<td>".$td."</td>\n";
}

function writeLI($li)
{
echo "<li>".$li."\n";
}

function outputArray(&$someArray, $cbFnc)
{
$len = sizeof($someArray);
$i=0;
while($i < $len){
$cbFnc($someArray[$i]); // Here it is...
$i++;
}
}

/* In you code */

...<table>
...<tr>
/* just pass the name of the function as a string to $cbFnc*/
outputArray($myArray, "writeTD&quot

;
...</tr>
...</table>

OR
...<ul>
//single quotes work fine also
outputArray($myArray, 'writeLI');
...</ul>

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function as the argument of another function?

fowlerlfc

MIS

sleipnir214

Programmer

fowlerlfc

MIS

sleipnir214

Programmer

RbgoWeb

Programmer

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