What is the main issue highlighted in the PHP script provided?

The main issue highlighted in the PHP script is the incorrect use of the `==` operator for comparison within the `if` statement. The `==` operator is used for loose comparison, which can lead to unexpected results. To ensure strict comparison, the `===` operator should be used instead.

// Incorrect comparison using the == operator
$number = "10";
if($number == 10) {
    echo "Number is 10";
} else {
    echo "Number is not 10";
}

// Correct comparison using the === operator
$number = "10";
if($number === 10) {
    echo "Number is 10";
} else {
    echo "Number is not 10";
}