Comma separated string to parent child relationship array php - php

Question

I have a comma separated string like
$str = "word1,word2,word3";
And i want to make a parent child relationship array from it.
Here is an example:

Answer 1

Try this simply making own function as
$str = "word1,word2,word3";
$res = [];
function makeNested($arr) {
if(count($arr)<2)
return $arr;
$key = array_shift($arr);
return array($key => makeNested($arr));
}
print_r(makeNested(explode(',', $str)));
Demo

Answer 2

function tooLazyToCode($string)
{
$structure = null;
foreach (array_reverse(explode(',', $string)) as $part) {
$structure = ($structure == null) ? $part : array($part => $structure);
}
return $structure;
}

Answer 3

Please check below code it will take half of the time of the above answers:
<?php
$str = "sports,cricket,football,hockey,tennis";
$arr = explode(',', $str);
$result = array();
$arr_len = count($arr) - 1;
$prev = $arr_len;
for($i = $arr_len; $i>=0;$i--){
if($prev != $i){
$result = array($arr[$i] => $result);
} else {
$result = array ($arr[$i]);
}
$prev = $i;
}
echo '<pre>',print_r($result),'</pre>';

Answer 4

Here is another code for you, it will give you result as you have asked :
<?php
$str = "sports,cricket,football,hockey,tennis";
$arr = explode(',', $str);
$result = array();
$arr_len = count($arr) - 1;
$prev = $arr_len;
for($i = $arr_len; $i>=0;$i--){
if($prev != $i){
if($i == 0){
$result = array($arr[$i] => $result);
}else{
$result = array(array($arr[$i] => $result));
}
} else {
$result = array ($arr[$i]);
}
$prev = $i;
}
echo '<pre>',print_r($result),'</pre>';