Why sizeof() function uses in PHP?

<?php
$cars=array("Volvo","BMW","Toyota");
echo sizeof($cars);
?>

How many types of array are available in php?

Which of the following PHP function will return true if a variable is an array or false if it is not an array?

Which array function will add a value to the end of an array?

What will be the output of the following PHP code?

<?php 

$animals = array("cow","cat",array("tiger","lion"),"goat");

echo count($animals,1);

?>

What is the output of the following php code?

<?php
 $alpha_arr = array ("Free", "Online", "Test");
 echo (next($alpha_arr ));
 ?>

What will be the output of the following PHP code?

< ?php 
    $fruits = array ("A", "B", "C", "D");
    $fruits = array_flip($fruits);
    echo ($fruits[0]);
?>

What will be the output of the following PHP code?

<?php $arr=array("a"=>"red","b"=>"green","c"=>"blue");
echo array_search("red",$arr);
?>

What will be the output of the following PHP code?

< ?php 
    $number = array ("10", "Freeonlinetest", 2);
    echo (array_sum ($number));
?>

What will be the output of the following PHP code?

<?php
$name_array = array("Subha Kalyan", "Swasat Kalyan", "Paban Kalyana");
$age = array("6", "2", "43");
$c = array_combine($name_array , $age);
print_r($c);
?>

What will be the output of the following PHP code?

<?php
$animals = array("Cow", "Cat", "Dog", "Cow", "Dog");
print_r(array_count_values($animals));
?>