<?php
$ch = ' We study the php and css.... ';
echo strlen( $ch ); ?>

30

<?php
$ch = ' We study the php and css.... ';
$trimme = trim($ch);
echo strlen( $ch ); ?>

28

<?php
$ch = ' We study the php and css.... ';
$trimme = trim($ch);
$removePeriod = str_replace('.', '', $trimme); echo strlen( $removePeriod ); ?>

24

<?php
$address = "non@domain.fr";
$arobase = "@";
$position = strpos($address, $arobase); echo $position . '
'; echo substr($address, 4); ?>

3
domain.fr

<?php
$ch = "Dear Person,
Thank you for joining us. Thank you person for your participation. It very kind of you.
See you soon person";
echo str_ireplace("Person", "Fomba", $ch ); ?>

Dear Fomba,
Thank you for joining us. Thank you Fomba for your participation. It very kind of you.
See you soon Fomba

<?php
$name = "Starchirs";
$mail = "KOUBA01@domin.fr";
echo strtoupper($name ); echo "
"; echo strtolower($mail ); ?>

STARCHIRS
kouba01@domin.fr

<?php
$ch = "STIMEET";
echo strrev($ch ); ?>

TEEMITS