Foreach loop working, but outputting "invalid argument"? - php

Question

I hope to give enough information here, but I am confused as to why the foreach loop works, it gets each data and outputs it in an li but I am getting an invalid argument error?
Here is the result of the var_dump
array(1) { ["questions"]=>
array(2) { ["title"]=> string(5) "Keanu" [1]=>
array(1) { ["questionlist"]=> array(2) { [0]=>
array(1) {
["a-question"]=> string(1) "1" } [1]=> array(1) {
["a-question"]=> string(5) "civil" } } } } }
Here is my foreach statement
foreach($questions['questions'] as $key => $value){
foreach($value['questionlist'] as $key => $subquestion){ //line 119
echo '<li>'.$subquestion['a-question'].'</li>';
}
}
$questions is a variable used to get the data from the database like this.
$questions = $wpdb->get_row("SELECT * FROM $table_name ORDER BY id DESC LIMIT 1" , ARRAY_A);
The data comes from ajax, I modify the ajax $_POST like this before sending to the database.
// Add modifications
$questions['questions'] = $_POST['questions']['data'];
// DB data
$name = $wpdb->escape($questions['questions']['title']);
$data = $wpdb->escape(json_encode($questions));
Screenshot:
I am not sure why I am getting the invalid argument, I suspect its because the array may not be formatted properly, if you need any more information let me know.
A Solution: Thanks to #didierc
I used his code and modified it a bit to display my data in a loop, basically all I did was add another foreach.
foreach($questions['questions'] as $key => $value){
if(is_array($value) && isset($value[ 'questionlist'])){
foreach($value as $key => $subquestion){ //line 119
foreach ($subquestion as $key => $value){
// This loops all the ['a-question'] data
echo '<li>''.$value['a-question'].''</li>';
}
}
}
}

Answer 1

Try this:
foreach ($questions['questions'] as $key => $value) {
if (is_array($value) && isset($value[ 'questionlist'])) {
foreach ($value['questionlist'] as $subnum => $subquestion) {
foreach ($subquestion as $qtitle => $qanswer) {
With variable names hopefully explicit enough. That should get you started.
NB: The data is probably easier to understand when formatted as below:
array(1) {
["questions"]=> array(2) {
["title"] => string(5) "Keanu"
[1] => array(1) {
["questionlist"]=> array(2) {
[0]=> array(1) {
["a-question"]=> string(1) "1"
}
[1]=> array(1) {
["a-question"]=> string(5) "civil"
}
}
}
}
}