I have the following if condition:
if ( $items[ $count + 1 ]->menu_item_parent != $parent_id && $submenu && $items[ $count + 1 ]->menu_item_parent != $item->ID) { //something } I get the notice:
Undefined offset: 13 So I assume the 13 does not exist in the $items array and it can be avoided by checking with in_array. However I'm unsure how I can use that function in the above condition.
if ( isset($items[ $count + 1 ]) && $items[ $count + 1 ]->menu_item_parent != $parent_id && $submenu && $items[ $count + 1 ]->menu_item_parent != $item->ID) { //something } 
You could first check if $items[$count + 1] exists. Like
if( //check first if $items[$count + 1] exists, else it breaks here isset($items[ $count + 1 ] ) //now you know $item[$count + 1] exists, so you can continue && ( $items[$count + 1]->menu_item_parent != $parent_id && $submenu && $items[ $count + 1 ]->menu_item_parent != $item->ID ) ){ //something } You should use a prefix test using isset method.
The call would look like that:
if (isset($items[ $count + 1 ])) { //do stuffs} Ok so the in_array docs say:
in_array ( mixed $needle , array $haystack)
Where
needle = the searched value
haystack = the array
And you are not looking for the value, you're looking for the key
When you look at the bottom under see also, it says:
which is what you are looking for:
array_key_exists() returns TRUE if the given key is set in the array. key can be any value possible for an array index.
Perfect! Exactly what you want!
array_key_exists ( mixed $key , array $array )
where
key = value to check
array = array (duh!)
if ( array_key_exists($count + 1, $items)) $items[ $count + 1 ]->menu_item_parent != $parent_id && $submenu && $items[ $count + 1 ]->menu_item_parent != $item->ID) { //something } 