php return an empty array after foreach

Question

Can I avoid the empty array that generate by foreach ?
here is my code

$file="test.txt";
$open = file_get_contents($file);
$lines = explode(PHP_EOL, $open);
foreach($lines as $line){
    $domain = preg_split('/\s+/', $line,-1,PREG_SPLIT_NO_EMPTY);
    echo "<pre>";
    var_dump($domain);
    echo "$domain[0] OK";
    echo "</pre>";
}

test.txt contains this

www.google.com  2.2.2.3
www.test.com    2.2.2.3
www.example.com 2.2.2.3

after I ran my script the result is this

array(2) {
  [0]=>
  string(14) "www.google.com"
  [1]=>
  string(7) "2.2.2.3"
}
www.google.com OK
array(2) {
  [0]=>
  string(12) "www.test.com"
  [1]=>
  string(7) "2.2.2.3"
}
www.test.com OK
array(2) {
  [0]=>
  string(15) "www.example.com"
  [1]=>
  string(7) "2.2.2.3"
}
www.example.com OK
array(0) {
}
 OK

What cause the array(0) to appear?
There's no new line after www.example.com or other element.
Can I remove it or simply don't get it generated?

Why not just use file function?foreach(file($file) as $line) instead of file_get_contents + explode — Lake
– Lake, Commented Jul 20, 2012 at 7:28

GolezTrol · Accepted Answer · 2012-07-20 07:14:55Z

2

There's an extra linebreak or other whitespace character after the last domain.

Trim the text file contents first:

$open = trim(file_get_contents($file));

You could also check if the line isn't empty inside the loop.

$file="test.txt";
$open = trim(file_get_contents($file));  // Either this..
$lines = explode(PHP_EOL, $open);
foreach($lines as $line){

    if ($line === '') // Or this
        continue;


    $domain = preg_split('/\s+/', $line,-1,PREG_SPLIT_NO_EMPTY);
    echo "<pre>";
    var_dump($domain);
    echo "$domain[0] OK";
    echo "</pre>";
}

answered Jul 20, 2012 at 7:14

GolezTrol

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1 Comment

tommyhsu Over a year ago

thanks, I've try trim but it is inside the foreach loop so it donesn't work but now it works well!

hsz · Accepted Answer · 2012-07-20 07:15:51Z

0

Check what contains the last line with:

var_dump($line);

If it contains empty string, just add some check:

if ( empty($line) ) {
  continue;
}

answered Jul 20, 2012 at 7:15

hsz

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Comments

hakre · Accepted Answer · 2012-07-20 07:23:14Z

0

I suggest you use the SplFileObject instead:

$path = "test.txt";
$file = new SplFileObject($path);

$file->setFlags(
    SplFileObject::DROP_NEW_LINE   # new line characters at the end of line
    | SplFileObject::SKIP_EMPTY    # skip empty lines, e.g. the one at the end
);

foreach ($file as $line)
{
    $domain = preg_split('/\s+/', $line, -1, PREG_SPLIT_NO_EMPTY);

    echo "<pre>", var_dump($domain), "$domain[0] OK", "</pre>";
}

It not only has support for your issue build in (see the flags) but also parses the file line by line, so for larger files it would not shift it completely into the memory. See as well the file function.

answered Jul 20, 2012 at 7:23

hakre

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1 Comment

joeni Over a year ago

I would also suggest the SplFileObject, little side note: in order to let SKIP_EMPTY do its job you also need READ_AHEAD: stackoverflow.com/questions/32806111/…

Community · Accepted Answer · 2020-06-20 09:12:55Z

You're better off using preg_match_all for such an example:

Just names

<?php
$file = 'test.txt';
$open = file_get_contents($file);
preg_match_all('/^\S+/m', $open, $matches);
print_r($matches[0]);
Array
(
    [0] => www.google.com
    [1] => www.test.com
    [2] => www.example.com
)

Names and numbers

<?php
$file = 'test.txt';
$open = file_get_contents($file);
preg_match_all('/^(\S+)\s+(\S+)$/m', $open, $matches);
print_r($matches);
Array
(
    [0] => Array
        (
            [0] => www.google.com  2.2.2.3
            [1] => www.test.com    2.2.2.3
            [2] => www.example.com 2.2.2.3
        )

    [1] => Array
        (
            [0] => www.google.com
            [1] => www.test.com
            [2] => www.example.com
        )

    [2] => Array
        (
            [0] => 2.2.2.3
            [1] => 2.2.2.3
            [2] => 2.2.2.3
        )

)

$result = array_combine($matches[1], $matches[2]);
print_r($result);
Array
(
    [www.google.com] => 2.2.2.3
    [www.test.com] => 2.2.2.3
    [www.example.com] => 2.2.2.3
)

Krishna · Accepted Answer · 2012-07-20 07:43:23Z

0

I have tested your code and found that it's working perfectly... I got this output by same code

  array(2) {
  [0]=>
  string(14) "www.google.com"
  [1]=>
  string(7) "2.2.2.3"
}
www.google.com OK

array(2) {
  [0]=>
  string(12) "www.test.com"
  [1]=>
  string(7) "2.2.2.3"
}
www.test.com OK

array(2) {
  [0]=>
  string(15) "www.example.com"
  [1]=>
  string(7) "2.2.2.3"
}
www.example.com OK

I think there is new line [enter] in your text file please remove it using backspace and it will work fine..

answered Jul 20, 2012 at 7:43

Krishna

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1 Comment

tommyhsu Over a year ago

it's solve after I use trim(file_get_contents($file)). I think there might be space or tab (\n or \t) somewhere else.

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