What are the potential issues with copying and pasting code without understanding it in PHP development?

Potential issues with copying and pasting code without understanding it in PHP development include introducing bugs, security vulnerabilities, and difficulties in maintaining and troubleshooting the code. To solve this issue, it is important to take the time to understand the code being copied and pasted, make necessary modifications to fit the specific context, and test thoroughly before deploying.

// Example of modifying copied code to fit specific context
// Original code: $result = someFunction($param);
// Modified code: 
$param = sanitizeInput($param);
$result = someFunction($param);