1 ) strlen: to fin the length of the string
<?php
echo strlen("sharp tutorial!"); // outputs 14
?>
2) str_world_count: to count the word in the given string
<?php
echo str_word_count("sharp tutorial!"); // outputs 2
?>
3) strrev: it reverse the given string
<?php
echo strrev("sharp!"); // outputs !prahs
?>
4) strpos: it gives the index of the given substring into main string
<?php
echo strpos("sharp tutorial", "tutorial"); // outputs 6
?>
5) str_replace: it replace a given string with another string into the main string
<?php
echo str_replace("tutorial", "totorial", "sharp tutorial"); // outputs sharp totorial
?>