What are some best practices for managing arrays in PHP to avoid issues with missing or incomplete data?

When managing arrays in PHP, it is important to check for missing or incomplete data to avoid potential issues with your code. One way to handle this is by using isset() or empty() functions to verify if a key exists in an array before accessing it. Additionally, you can use array_key_exists() function to check if a specific key exists in an array to avoid errors related to missing data.

// Example of checking if a key exists in an array before accessing it
$array = ['key1' => 'value1', 'key2' => 'value2'];

if(isset($array['key1'])){
    // key1 exists, safe to access
    echo $array['key1'];
} else {
    // key1 does not exist
    echo 'Key1 does not exist';
}