How can one prevent unexpected behavior when using weakly typed languages like PHP?

To prevent unexpected behavior when using weakly typed languages like PHP, one should always explicitly declare variable types and use strict comparison operators to ensure that variables are of the expected type before performing operations on them. Additionally, validating user input and sanitizing data can help prevent unexpected behavior caused by incorrect data types.

// Example of explicitly declaring variable types and using strict comparison operators
$number1 = (int) $number1;
$number2 = (int) $number2;

if ($number1 === $number2) {
    // Perform operations on the variables
} else {
    // Handle the case where the variables are not of the same type
}