In PHP and during a foreach loop, how can I replace empty array values with a string?

Question

I'm using the library PHP Simple HTML DOM Parser and my array is working A-OK, now in some of the URLs parsed the element simply does not exist (which is OK) yet I would like to create a condition that would replace empty array values with a string such as 'not found'.

How would I be able to accomplish this?

Here is the code:

$memb1 = 'http://www.xyz1.org';
$memb2 = 'http://www.abc3.org';
$memb(n) = '...etc...etc'

$teams = array(
    array("url" => $memb1, "selector" => ".product-list >
                      table:nth-child(1) >
                      tbody:nth-child(1) >
                      tr:nth-child(2) >
                      td:nth-child(2) > a"),
    array("url" => $memb2, "selector" => ".product-list >
                      table:nth-child(1) >
                      tbody:nth-child(1) >
                      tr:nth-child(2) >
                      td:nth-child(2) > a"),
    array("url" => $memb(n), "selector" => ".product-list >
                      table:nth-child(1) >
                      tbody:nth-child(1) >
                      tr:nth-child(2) >
                      td:nth-child(2) > a"),...etc...etc

And my Foreach loop looks like this:

foreach($teams as $site) {
    $url = $site["url"];
    $html = file_get_html($url);
    foreach ($html->find($site["selector"]) as $a) {
        $links[] = $a->href; break;
    }
}
?>
<pre>
<?php print_r($links);?>
</pre>

So I'll reiterate for clarification; The foreach loop pushes into index the value of the found href links from 'selector'. When an element is not found it just skips to the next index, I would like to create a condition that would check if that element exists, if not: push into that index value a string.

so let's say that index 2, 4, and 5 href's do not exist, the expected result should look like this:

Array
(
    [0] => http://www.abcd.com/etc/etc
    [1] => http://www.gfege.com/etc/etc
    [2] => Not Found
    [3] => http://www.asdad.com/etc/etc
    [4] => Not Found
    [5] => Not Found
)

I have no idea where to place that condition and the right syntax that would fit in foreach.

So you want to see if your array[key] is empty() or not and if( empty( array[key] ) ) set array[key] = "Not Found"; right ? :) — ODelibalta
– ODelibalta, Commented Jul 21, 2016 at 14:16
Are you saying the $links[] = $a->href; doesn't get run at all on <a> tags without href? That's a bit strange, the foreach() should include all <a> tags that matches the selector regardless of attributes to it.. — kb.
– kb., Commented Jul 21, 2016 at 14:16
Are you expecting that $html->find($site["selector"]) finds only one a tag ? — jbrtrnd
– jbrtrnd, Commented Jul 21, 2016 at 14:17
@ODeblibalta The keys are not known before hand so there is no way to retroactively patch the array. There doesn't seem to be any gap in his current output array (but hard to know for sure without example of current output). — kb.
– kb., Commented Jul 21, 2016 at 14:18
@ODelibalta - yes, but from 3 answers here, none was right, would you like to syntax that with the code? That's basically part of the problem, I don't know where to place the condition. Thanks bud. — clusterBuddy
– clusterBuddy, Commented Jul 21, 2016 at 14:39

matthewpark319 · Accepted Answer · 2016-07-21 14:24:49Z

0

Try an if statement that checks if

$a->href

is empty. So the code would look something like this:

if (empty($a->href)) {
    links[] = "Not Found";
} else {
    links[] = $a->href;
}

answered Jul 21, 2016 at 14:24

matthewpark319

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1 Comment

clusterBuddy Over a year ago

I tested it, it looks great but it doesn't work, it gives me the same output.

score 0 · Accepted Answer · 2016-07-21 14:38:33Z

0

If I understand what you want :

$links[] = ($a->href != "") ? $a->href : "Not Found";

edited Jul 21, 2016 at 14:38

answered Jul 21, 2016 at 14:19

user6599592

3 Comments

clusterBuddy Over a year ago

hi, thanks for the answer, but I tested it and it doesn't work, it just prints the same output as before.

user6599592 Over a year ago

Can you give the output of print_r($links) if $links contains an invalid key ?

clusterBuddy Over a year ago

Hey Dario, I couldn't understand your question re 'invalid key' (there was no such error) it simply returns the same output as before, nothing changed.

ODelibalta · Accepted Answer · 2016-07-21 14:54:42Z

0

Looks like there is a bit of confusion here so I am going to write every possible thing that I interpreted as something you want to achieve and I am going off from one of your sentences in the post

I would like to create a condition that would check if that element exists, if not: push into that index value a string.

If you want to see if a specific array key exists, use this

$search_array = array('first' => 1, 'second' => 4);
if (array_key_exists('first', $search_array)) {
    echo "The 'first' element is in the array";
}

You can change the string 'first' to whatever string variable you have in your loop. If you want to see if array key has a "truthy" value, use this:

isset($array['foo'])

Again, you can replace 'foo' with a variable.

If you want to see a specific value exists in an array, use this

$os = array("Mac", "NT", "Irix", "Linux");
if (in_array("Irix", $os)) {
    echo "Got Irix";
}

If you are checking string values, it is a good idea to trim the strings before hand. I've had issues in the past where a variable was set to something weird like $var = " " and it acted like it was a true string with length. I like doing something like this

if( strlen( trim($text) ) > 0) { ... }

If any one of those conditions are what you want, just set that index value to a string that you want.

That pretty much sums it up for me. I am sorry I did not understand your question very well and from the looks of it, there are others who feel the same. Good luck to you.

answered Jul 21, 2016 at 14:54

ODelibalta

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2 Comments

clusterBuddy Over a year ago

Hey thank you so much for long and detailed answer, I was going over it and I'll go over it again, but I can't really see what's the issue with my question (and I'm a bit surprised that you actually went and took the position of delegating for other people what they understand or don't understand, that kind of gave a sour note at the end...) In anycase, If you can see $memb variables, they just hold strings of my sites, the array later on is built as 'url'=>'a url' and 'selector'=>'any tag in the DOM' and that array is built for every $memb.

clusterBuddy Over a year ago

When looping through it, if the 'selector' value (say "input") is not found, it just skips and continues the index, business as usual. In anycase, just to emphasize, there are 8 $memb adresses and the foreach prints only 5, I have actually checked and those missing 3 don't have those DOM elements, which is fine, I just want to push into those missing elements, a string. It can't be simplified or more understandable than that.

jbrtrnd · Accepted Answer · 2016-07-22 07:29:21Z

0

This is what you need :

<?php

foreach($teams as $site) {
    $url     = $site["url"];
    $html    = file_get_html($url);
    $anchors = $html->find($site["selector"];

    if ($anchors !== null) {
        foreach ($html->find($site["selector"]) as $a) {
            $links[] = $a->href; break;
        }
    } else {
        $links[] = 'Not found';
    }
}

?>

But keep in mind that if your selector returns more than one <a /> tag, your final array will not be as you expect.

answered Jul 22, 2016 at 7:29

jbrtrnd

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