What are the differences between the two provided functions for removing duplicate values in PHP arrays, and which one is more efficient?

When working with PHP arrays, it is common to encounter duplicate values that need to be removed. One way to achieve this is by using the `array_unique()` function, which removes duplicate values from an array. Another approach is to use a loop to iterate over the array and build a new array with unique values. The `array_unique()` function is more efficient and concise compared to manually iterating over the array.

// Using array_unique() function to remove duplicate values
$array = [1, 2, 2, 3, 4, 4, 5];
$uniqueArray = array_unique($array);
print_r($uniqueArray);