Get unique value from an array php - php

Question

I want to display only unique strings and I have this code:
$sql = "SELECT tags FROM videos";
$result = mysqli_query($mysqli, $sql);
while ($rez = $result->fetch_assoc()) {
$array = array_filter(explode(',', $rez['tags']));
$array = array_unique($array);
foreach ($array as $value) {
$value = ltrim($value);
$value = str_replace(" ", "-", $value);
echo '' . $value . '<br>';
}
}
I have put an array_unique like this:
$array = array_unique($array);
But it returns this:
word-word
word
word2
word3
word-word
It doesn't print only unique values. What is wrong?

Answer 1

Think the problem is because the strings are being processed after the array_unique operation rather than before it. Try the following instead:
$sql = "SELECT tags FROM videos";
$result = mysqli_query($mysqli, $sql);
while ($rez = $result->fetch_assoc()) {
$array = array_filter(explode(',', $rez['tags']));
foreach ($array as $value) {
$value = ltrim($value);
$value = str_replace(" ", "-", $value);
}
$array = array_unique($array);
foreach ($array as $value) {
echo '' . $value . '<br>';
}
}

Answer 2

I have resolved, i will post code may be will be good for someone!
$sql = "SELECT tags FROM videos";
$result = mysqli_query($mysqli, $sql);
$alltags=array();
while ($rez = $result->fetch_assoc()) {
$array = array_filter(explode(',', $rez['tags']));
foreach ($array as $key => $value) {
$value = ltrim($value);
$value = str_replace(" ", "-", $value);
$alltags[]=$value;
}
}
$array=array_unique($alltags);
foreach ($array as $value) {
echo '' . $value . '<br>';
}

Answer 3

Explode your string.
Trim outer spaces from each element.
Replace inner spaces with hyphen in each element.
Only keep non-empty elements.
Only keep unique elements (using double array_flip).
Display results.
Code: (Demo)
while($rez=$result->fetch_assoc()) {
$array=explode(',',$rez['tags']); // split into elements
foreach($array as $v){
$v=str_replace(" ","-",trim($v)); // remove outer spaces, replace inner spaces
if($v){$clean[]=$v;} // retain non-empty values
}
$clean=array_flip(array_flip($clean)); // double flip is faster than array_unique
foreach($clean as $v){
echo "$v<br>";
}
}
Alternatively, you could do all of the value and html prep in the first foreach loop and then use implode to display the batch. This will remove the potentially unnecessary trailing from final element:
Code:
$rez['tags']=' , word , word-word, word2 , word word, word3,';
$array=explode(',',$rez['tags']); // split into elements
foreach($array as $v){
$v=str_replace(" ","-",trim($v)); // remove outer spaces, replace inner spaces
if($v){
$clean[]="$v"; // prep non-empty values for display
}
}
echo implode("<br>",array_unique($clean));
Output:
word<br>
word-word<br>
word2<br>
word3