String Parts in PHP

Given a string:

<?php
	$str = 'ab-cd-ef';
?>

Using the strchr function, output the following string to the screen:

'-cd-ef'

Given a string:

<?php
	$str = 'ab-cd-ef';
?>

Using the strrchr function, output the following string to the screen:

'-ef'

Given a string:

<?php
	$str = 'ab--cd--ef';
?>

Using the strstr function, output the following string to the screen:

'--cd--ef'

Given a string:

<?php
	$str = 'программирование-на-php';
?>

Using the mb_strrchr function, output the part of the string after the last hyphen:

'-php'

Given a string:

<?php
	$str = 'Привет-Мир-Пока';
?>

Using the mb_strrichr function (case-insensitive) find the substring starting from the first occurrence of 'мир':

'-Мир-Пока'

Given a string:

<?php
	$str = 'Функции-для-работы-со-строками';
?>

Using the mb_strstr function, output the part of the string starting from the first occurrence of 'работы':

'-работы-со-строками'

Given a string:

<?php
	$str = 'ппп ррр ссс ттт ууу';
?>

Using mb_stristr, find the substring starting from 'РРР' (case-insensitive).

'ррр ссс ттт ууу'

Given a string:

<?php
	$str = 'Тестирование-многобайтовых-функций';
?>

Using the mb_strrchr function, output the part of the string after the last hyphen:

'-функций'

Given a string:

<?php
	$str = 'Пример-Поиска-Подстроки-В-Тексте';
?>

Using the mb_strrichr function (case-insensitive) find the substring starting from the first occurrence of 'тексте':

'-В-Тексте'