Shortest way to output 0 if meta does not have value / is empty

Question

Hope that title makes sense, I have a few meta fields that I want to output 0 if they are empty.

I'm currently outputting the values with this:

<?php meta('some-field'); ?>

Edit: the above code will echo out the value

You don't need the empty() function call, because null and empty string would cast to false. http://php.net/manual/en/language.types.boolean.php — Gerifield, Dec 24 '14 at 16:47

score 1 · Accepted Answer · answered Dec 24 '14 at 16:44

1

For example use the ternary operator. After PHP 5.3:

echo meta('some-field') ? : 0;

Before PHP 5.3:

echo meta('some-field') ? meta('some-field') : 0;

answered Dec 24 '14 at 16:44

Gerifield

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echo meta('some-field') ? : 0; seems to output an additional 0 even when the meta has a value so value of word is now word0 and 4000 is 40000, couldn't get the other suggestions working really. – Alex Szymanowski Dec 24 '14 at 17:06
Your function returns with that value and don't try to print it? – Gerifield Dec 24 '14 at 17:14
Not sure what you mean ? – Alex Szymanowski Dec 24 '14 at 17:17
Your meta function ends with return $something and not echo $something? Just to be sure. :) – Gerifield Dec 24 '14 at 17:19
Yeah I believe it echos it using https://wordpress.org/plugins/more-fields/ so that's the code I was using, I'm outputting the data into js Google charts to be exact. – Alex Szymanowski Dec 24 '14 at 17:27
Ah, okay, then try Simone Nigro's solution with output buffering, because it'll catch the echo's result! – Gerifield Dec 24 '14 at 18:05
Tried that seems to break the page :( did a code check and got Fatal error: Can't use function return value in write context in your code on line 1 – Alex Szymanowski Dec 24 '14 at 18:48
Ended up using it but before the code that I was using is generated so works perfectly Thank you for the help :) – Alex Szymanowski Dec 26 '14 at 16:28

Simone Nigro · Answer 2 · 2014-12-24T19:08:03.603

1

assuming meta() write and not return anything...

function callback($buffer) {
    // check if buffer is empty, else return 0
    return (!empty($buffer)) ? $buffer : 0;
}

// turn output buffering on. the output is stored in an internal buffer. 
// The callback function will be called when the output buffer is flushed
ob_start('callback');

meta('some-field');

// Flush the output buffer
ob_end_flush();

working example: http://phpfiddle.org/main/code/42rr-zh8j

assuming meta() return value and not write anything...

// Check if meta return value is empty, print meta value else print 0
echo ( !empty(meta('some-field')) ) ? meta('some-field') : 0;

edited Dec 24 '14 at 19:08

answered Dec 24 '14 at 16:48

Simone Nigro

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Good call with return! – Rizier123 Dec 24 '14 at 16:49
1

@Gerifield I know... but for a newbie is perhaps easier to understand – Simone Nigro Dec 24 '14 at 17:00
I get Fatal error: Can't use function return value in write context in your code on line 1 on checking my code cause it seems to break the page not sure what to do.. – Alex Szymanowski Dec 24 '14 at 18:49
@AlexSzymanowski There is an error in your code between `ob_start` and `ob_end_flush` – Simone Nigro Dec 24 '14 at 19:01

score 0 · Answer 3 · answered Dec 24 '14 at 17:22

you can wrap meta() in a custom function of your own:

function myMeta($key, $default = '0') {
   $meta = meta($key);
   return empty($meta) ? $default : $meta;
}

and use it instead of meta:

myMeta('some-field');
myMeta('some-field', 'other-default-value');

Shortest way to output 0 if meta does not have value / is empty

3 Answers3