21.
Which PHP control structure is used to execute a block of code based on the evaluation of multiple conditions?
22.
What is the output of the following PHP code?

<?php
$i = 1;
while ($i <= 3) {
echo "The number is: $i
";
$i++;
if ($i == 2) {
continue;
}
}
?>
23.
Which PHP control structure is used to evaluate a single expression and execute a block of code based on the result of that expression?