How can the use of isset() function help prevent duplicate entries in an array in PHP?

When adding new entries to an array in PHP, it is important to check if the entry already exists to prevent duplicates. The isset() function can be used to check if a specific key already exists in the array before adding a new entry. By using isset() before adding a new entry, you can avoid duplicate entries in the array.

// Example code to prevent duplicate entries in an array using isset() function
$myArray = array("apple", "banana", "orange");

$newEntry = "banana";

if (!isset($myArray[array_search($newEntry, $myArray)])) {
    $myArray[] = $newEntry;
}

print_r($myArray);