Question:

(a) What are the differences between include(), require() and include_once()?

(b) Convert the below if-elseif code to its equivalent switch case version:

$day = 'Wednesday';
if ($day == 'Monday') {
echo 'Wish you a fresh start!';
}
elseif ($day == 'Wednesday') {
echo 'Keep going. Good luck!';
}
elseif ($day == 'Friday') {
echo 'Happy weekend!';
}
else {
echo 'Good day!';
}

(c) Describe the two kinds of arrays supported by PHP and provide suitable code fragments to illustrate your answer?

(d) Write a function that returns the result of a basic arithmetic operation like addition, subtraction, multiplication and division based on two supplied operands passed as arguments. The function should accept two mandatory arguments, i.e. the first and second operands and a third optional argument for the operator (default operator value is addition).

(e) Consider the following PHP code:

for ($i=1; $i<=3; $i++)
{
for ($j=1; $j<=$i; $j++)
{
echo 'X';
}
echo '
';
}

The above code fragment uses a for loop construct to print out Output A. Using the While construct, rewrite the above code fragment to print out the same output.