Implementing strlen() in a loop - php

Question

I've got a string here with names of students (leerlingen) and im trying to follow the exercise here.
The code shows the length of the full string.
Next up would be use a loop to check who has the longest name, but how to implement strlen() in a loop?
// change the string into an array using the explode() function
$sleerlingen = "Kevin,Maarten,Thomas,Mahamad,Dennis,Kim,Joey,Teun,Sven,Tony";
$namen = explode(" ", $sleerlingen);
echo $namen[0];
echo "<br><br>";
//determin the longest name by using a loop
// ask length
$arraylength = strlen($sleerlingen);
sleerlingen = $i;
for ($i = 1; $i <= 10; $i++) {
echo $i;
}
echo $arraylength;
?>

Answer 1

You used bad separator in your explode function, in string there is no space.
This should work (I didn't try it). In foreach loop you check current length with the longest one and if the current is longer, just save it as longest.
<?php
$sleerlingen = "Kevin,Maarten,Thomas,Mahamad,Dennis,Kim,Joey,Teun,Sven,Tony";
$names = explode(',', $sleerlingen);
$longest;
$longest_length = 0;
foreach ($names as $item) {
if (strlen($item) > $longest_length) {
$longest_length = strlen($item);
$longest = $item;
}
}
echo 'Longest name: ' . $longest . ', ' . $longest_length .' chars.';
?>

Answer 2

You can create a custom sort function to sort the array based on the strings length. Then you can easily take the first key in the array.
<?php
$sleerlingen = "Kevin,Maarten,Thomas,Mahamad,Dennis,Kim,Joey,Teun,Sven,Tony";
$namen = explode(",", $sleerlingen); // changed the space to comma, otherwise it won't create an array of the string.
function sortByLength($a,$b){
return strlen($b)-strlen($a);
}
usort($namen,'sortByLength');
echo $namen[0];
?>