How can PHP developers avoid complications when transferring code to their arrays?

When transferring code to arrays in PHP, developers should ensure that the data being transferred is properly sanitized and validated to avoid complications such as security vulnerabilities or unexpected behavior. Using functions like `filter_input()` or `htmlspecialchars()` can help sanitize input data before adding it to an array. Additionally, developers should always validate the data against expected formats or values to prevent errors in the array structure.

// Example of transferring code to an array with proper sanitization and validation
$input_data = $_POST['input_data']; // Get input data from form submission

// Sanitize input data using htmlspecialchars
$sanitized_data = htmlspecialchars($input_data);

// Validate data against expected format (e.g. numeric value)
if(is_numeric($sanitized_data)) {
    $my_array['key'] = $sanitized_data; // Add sanitized data to array
} else {
    // Handle validation error
    echo "Invalid input data";
}