Can i nest a foreach within foreach? - php

Question

I have an array: $categories = array("item1", "item2", "item3");
I also have three arrays: $item1Array = array("hi", "items");, $item2Array = array("hi", "items");, $item3Array = array("hi", "items");
I stated a foreach like this:
foreach ($categories as &$value) {
echo "<optgroup label='" . $value . "'>';
$nextArray = $value . "Array";
foreach($nextArray as &$nextValue) {
echo "<option value='" . $nextValue . "'>" . $nextValue . "</option>";
}
}
but it get an error Warning: invalid argument supplied for foreach().
Is there a way I can achieve this?

Answer 1

Yes, you could, by ${$nextArray}. but notice named variables is not good practice, you could use associative array instead.
And note you don't need to use reference in this case.
$categories = array("item1", "item2", "item3");
$item1Array = array("hi", "items");
$item2Array = array("hi", "items");
$item3Array = array("hi", "items");
foreach ($categories as $value) {
echo "<optgroup label='" . $value . "'>";
$nextArray = $value . "Array";
foreach(${$nextArray} as $nextValue) {
echo "<option value='" . $nextValue . "'>" . $nextValue . "</option>";
}
}

Answer 2

Of course, but as you can clearly see from the syntax highlighting of your post, you used a ' instead of a " at the end of the "optgroup" line.
Also, you could just use a nested array:
$categories = Array(
"item1"=>Array("hi","items"),
"item2"=>Array("hi","items"),
"item3"=>Array("hi","items"),
);
foreach($categories as $key=>$array) {
echo "<optgroup label='".$key."'>";
foreach($array as $value) {
echo "<option>".$value."</option>";
}
echo "</optgroup>";
}