是否可以在PHP的foreach语句中嵌入list函数？

Question

I've thought about this problem before but never got anywhere on it. I think I've done it with Python but never PHP.

Define a basic php array:

$arr = array (array(1,2,3), array(4,5,6), array(7,8,9));

Then run this snippet:

foreach ($arr as $row)
{
    list($a, $b, $c) = $row;
    echo "$a, $b, $c <br>";
}

This is so common, I must have done it a million times during my php career...but it seems a bit wasteful. $row is a temp variable and is never really used and the list()= line seems like it should be able to be put into the foreach bracket

Something like this (of course, this doesn't work):

foreach ($arr as list($a, $b, $c) = $row)
{
    echo "$a, $b, $c <br>";
}

Neither does:

foreach ($arr as list($a, $b, $c))
{
    echo "$a, $b, $c <br>";
}

Has anyone come up with a cool shortcut for this? Thanks!

Answer 1

Yes, kind of. Use this:

while( list( $key, list( $a, $b, $c ) ) = each( $array ) ) {
    // do stuff here
}

Note the use of list twice - each returns the key-value pair, and the value is also an array so we use list again.

You can also use list( , list( $a, $b, $c ) ), leaving out $key if you want. But I think that's kind of ugly syntax. ;)