How can the structure and organization of PHP scripts impact the occurrence of errors like unexpected variables or parse errors?

The structure and organization of PHP scripts can impact the occurrence of errors like unexpected variables or parse errors by ensuring that variables are declared and used correctly, and that the code is properly formatted and organized. To avoid unexpected variables, it's important to define variables before using them and to avoid typos or misspellings. Parse errors can be minimized by properly closing all parentheses, brackets, and quotes.

<?php

// Define variables before using them
$name = "John";
$age = 30;

// Properly format and organize the code
if ($age >= 18) {
    echo $name . " is an adult.";
} else {
    echo $name . " is a minor.";
}

?>