array_intersect with unknown number of arrays

[Markus Ernst]

Hi

I have a question regarding array_intersect() in PHP 4.3. There are several
arrays created on the fly, such as:

$values['apples'];
$values['bananas'];
$values['pears'];

To extract only the values they have in common I tried this:

$command = "array_intersect(";
for ($i=0; $i<count($values); $i++) {
$command .= "\$values['$values[$i]'],";
}
$command = substr($command, 0, -1);
$command .= ");";
$result = eval($command);

This does not seem to work and also is quite complicated. Does somebody know
a better solution?

Thanks
Markus

[Steve]

I have a question regarding array_intersect() in PHP 4.3. There are several
arrays created on the fly, such as:

$values['apples'];
$values['bananas'];
$values['pears'];

To extract only the values they have in common I tried this:

$command = "array_intersect(";
for ($i=0; $i<count($values); $i++) {
$command .= "\$values['$values[$i]'],";
}
$command = substr($command, 0, -1);
$command .= ");";
$result = eval($command);

This does not seem to work and also is quite complicated. Does somebody know
a better solution?

The user comments in the docs for array_intersect suggest using
call_user_func_array() to pass an arbitrary number of arguments.
Looks like you should be able to use:

$result = call_user_func_array( 'array_intersect', $values );

(untested, got to catch a bus!)

---
Steve

[Markus Ernst]

Steve wrote:
[...]

The user comments in the docs for array_intersect suggest using
call_user_func_array() to pass an arbitrary number of arguments.
Looks like you should be able to use:

$result = call_user_func_array( 'array_intersect', $values );

Works perfectly! I had even read this note, but as I did not understand the
examples provided I did not realize that it was what I looked for. Seems
like it's worth to have a closer look at PHP's function functions.

Thanks a lot for your input!

--
Markus