How can developers effectively transition from PHP4 to PHP5 without encountering major issues?

To effectively transition from PHP4 to PHP5 without encountering major issues, developers should first review the PHP5 migration guide to understand the changes and new features. They should then update their codebase to comply with PHP5 syntax and best practices, such as using object-oriented programming and built-in functions. Additionally, testing the code thoroughly in a PHP5 environment before deployment can help identify and resolve any compatibility issues.

// PHP4 code
$var = "Hello, World!";
echo $var;

// PHP5 code
$var = "Hello, World!";
echo $var;