How can I remove all empty values when I explode a string using PHP? [duplicate]

Question

I was wondering how can I remove all empty values when I explode a string using PHP for example, lets say a user enters ",jay,john,,,bill,glenn,,,"?

Thanks in advance for the help.

Here is part of the code that explodes user submitted values.

$tags = explode(",", $_POST['tag']);

Gnaw

Answer 1

E.g. via array_filter() or by using the PREG_SPLIT_NO_EMPTY option on preg_split()

<?php
// only for testing purposes ...
$_POST['tag'] = ",jay,john,,,bill,glenn,,0,,";

echo "--- version 1: array_filter ----\n";
// note that this also filters "0" out, since (bool)"0" is FALSE in php
// array_filter() called with only one parameter tests each element as a boolean value
// see http://docs.php.net/language.types.type-juggling
$tags = array_filter( explode(",", $_POST['tag']) ); 
var_dump($tags);

echo "--- version 2: array_filter/strlen ----\n";
// this one keeps the "0" element
// array_filter() calls strlen() for each element of the array and tests the result as a boolean value
$tags = array_filter( explode(",", $_POST['tag']), 'strlen' ); 
var_dump($tags);

echo "--- version 3: PREG_SPLIT_NO_EMPTY ----\n";
$tags = preg_split('/,/', $_POST['tag'], -1, PREG_SPLIT_NO_EMPTY);
var_dump($tags);

prints

--- version 1: array_filter ----
array(4) {
  [1]=>
  string(3) "jay"
  [2]=>
  string(4) "john"
  [5]=>
  string(4) "bill"
  [6]=>
  string(5) "glenn"
}
--- version 2: array_filter/strlen ----
array(5) {
  [1]=>
  string(3) "jay"
  [2]=>
  string(4) "john"
  [5]=>
  string(4) "bill"
  [6]=>
  string(5) "glenn"
  [8]=>
  string(1) "0"
}
--- version 3: PREG_SPLIT_NO_EMPTY ----
array(5) {
  [0]=>
  string(3) "jay"
  [1]=>
  string(4) "john"
  [2]=>
  string(4) "bill"
  [3]=>
  string(5) "glenn"
  [4]=>
  string(1) "0"
}

Howlett

@Howlett are you showing me 2 examples because $tags = preg_split('/,/', $_POST['tag'], -1, PREG_SPLIT_NO_EMPTY); alone works. Thanks! – Gnaw

@snag: Yes, he was showing two different ways to do it. The array_filter method he listed first is probably more standard, but as he mentioned, it could remove values you wanted to keep, so he included the preg_split method as an alternative. – Matrilateral

The reason this isn't working for some is because it doesn't handle whitespace. ie.`a,b,c, ,d". For that, I recommend array_filter with a callback. – Handicapper

If you want to make sure your array is re-indexed then wrap it in array_values – Valois

Answer 2

$tags = array_diff(explode(",", $_POST['tag']),array(""));

Valid

Answer 3

//replace multiple commas
$tags = preg_replace('/,+/', ',', $_POST['tag']);
//explode
$tags = explode(',', $tags);

Counterblow

Should be explode(',', $tags) and keeps the last empty element for the given string ",jay,john,,,bill,glenn,,,". – Howlett

still keeps the last empty element ;-) – Howlett

Answer 4

Simply try:

$tags = explode(", ", $_POST['tag']);

Adding space after comma, does the job!

Venomous