check if array has value php

1$myArr = [38, 18, 10, 7, "15"];
2
3echo in_array(10, $myArr); // TRUE
4echo in_array(19, $myArr); // TRUE
5
6// Without strict check
7echo in_array("18", $myArr); // TRUE
8// With strict check
9echo in_array("18", $myArr, true); // FALSE

1in_array ( mixed $needle , array $haystack [, bool $strict = FALSE ] ) : bool
2  
3// Without strict check
4echo in_array("18", $myArr); // TRUE
5// With strict check
6echo in_array("18", $myArr, true); // FALSE

1$os = array("Mac", "NT", "Irix", "Linux");
2if (in_array("Irix", $os)) {
3    echo "Got Irix";
4}
5if (in_array("mac", $os)) {
6    echo "Got mac";
7}

1The in_array() function is an inbuilt function in PHP. 
2The in_array() function is used to check whether a given value exists in an array or not.
3It returns TRUE if the given value is found in the given array, and FALSE otherwise.
4
5  <?php
6  
7$people = array("Peter", "Joe", "Glenn", "Cleveland");
8
9if (in_array("Glenn", $people))
10  {
11  echo "Match found";
12  }
13else
14  {
15  echo "Match not found";
16  }
17
18?>

1$allowedFileType = ['application/vnd.ms-excel','text/xls','text/xlsx','application/vnd.openxmlformats-officedocument.spreadsheetml.sheet'];
2  
3if(in_array($_FILES["file"]["type"],$allowedFileType))