Searching in Arrays in PHP

Задание 1

Given an array:

php<?php
  $arr = [1, 2, 3, 4, 5];
?>

Check that it contains an element with the value 3.

Задание 2

Given an array:

php<?php
  $arr = ['a', '-', 'b', '-', 'c', '-', 'd'];
?>

Find the position of the first element '-'.

Задание 3

Given an array:

php<?php
  $arr = ['a', '-', 'b', '-', 'c', '-', 'd'];
?>

Find the position of the first element '-' and remove it using the array_splice function.