How can copying and pasting code in PHP scripts lead to unexpected errors?

Copying and pasting code in PHP scripts can lead to unexpected errors due to potential syntax errors, missing dependencies, or conflicting variable names. To avoid these issues, it is essential to carefully review the copied code and ensure that it integrates seamlessly with the existing script. Additionally, you should test the functionality of the script after pasting the code to catch any errors early on.

// Example of a fix for copying and pasting code in PHP scripts
// Make sure to review and adjust the copied code as needed

// Copied code snippet
$newVariable = 10;
echo $newVariable;

// Existing script
$existingVariable = 5;
echo $existingVariable;

// Fix: Ensure variable names do not conflict
$newVariable = 10;
echo $newVariable;

$existingVariable = 5;
echo $existingVariable;