How can undefined offsets in PHP arrays be handled effectively to avoid errors like "Undefined offset: 15"?

When accessing array elements by index in PHP, it's important to check if the index actually exists before trying to access it to avoid "Undefined offset" errors. This can be done using the isset() function to verify if the index is set in the array before accessing it.

// Check if the offset exists before accessing it
if(isset($array[$index])) {
    // Access the element at the specified index
    $value = $array[$index];
    // Use $value as needed
} else {
    // Handle the case where the offset is undefined
    echo "Offset $index is not defined in the array";
}