What potential issue can arise when trying to access an undefined offset in a PHP array?

Trying to access an undefined offset in a PHP array can lead to an "Undefined offset" notice or warning. This means that the index you are trying to access does not exist in the array. To solve this issue, you can first check if the offset exists using the isset() function before trying to access it.

$array = [1, 2, 3];

// Check if the offset exists before accessing it
if(isset($array[3])) {
    $value = $array[3];
    echo $value;
} else {
    echo "Offset does not exist";
}