I would like to display some html code if a variable is not empty, else I would like to display nothing.
I've tried this code but doesn't work:
<?php
$web = the_field('website');
if (isset($web)) {
?>
<span class="field-label">Website: </span><a href="http://<?php the_field('website'); ?>" target="_blank"><?php the_field('website'); ?></a>
<?php
} else {
echo "Niente";
}
?>
if (!empty($web)) {
?>
<span class="field-label">Website: </span><a href="http://<?php the_field('website'); ?>" target="_blank"><?php the_field('website'); ?></a>
<?php
} else { echo "Niente";}
! before your empty call, as that is what the OP is looking for.isset will return true even if the variable is "". isset returns false only if a variable is null. What you should be doing:
if (!empty($web)) {
// foo
}
This will check that he variable is not empty.
Hope this helps
if ($web). No need for empty here, it just has the potential to hide mistakes unnecessarily.
if(!empty($var)) can create confusion, but I do agree that if ($var) is simpler.empty has the specific purpose of suppressing errors for nonexistent variables. You don't want to suppress errors unless you need to. The Definitive Guide To PHP's isset And empty explains the problem in detail.Simply use if ($web). This is true if the variable has any truthy value.
You don't need isset or empty since you know the variable exists, since you have just set it in the previous line.
I don't see how
if(!empty($var))can create confusion, but I do agree thatif ($var)is simpler. – vanneto Mar 8 '12 at 13:33Because
emptyhas the specific purpose of suppressing errors for nonexistent variables. You don't want to suppress errors unless you need to. The Definitive Guide To PHP'sissetAndemptyexplains the problem in detail. – deceze♦ Mar 9 '12 at 1:24
Focusing on the error suppression part, if the variable is an array where a key being accessed may or may not be defined:
if($web['status']) would produce:
Notice: Undefined index: status
if(isset($web['status']) && $web['status']) (2nd condition is not tested if the 1st one is FALSE) ORif(!empty($web['status'])).However, as deceze♦ pointed out, a truthy value of a defined variable makes !empty redundant, but you still need to remember that PHP assumes the following examples as FALSE:
null'' or ""0.0 0'0' or "0"'0' + 0 + !3So if zero is a meaningful status that you want to detect, you should actually use string and numeric comparisons:
Error free and zero detection:
if(isset($web['status'])){
if($web['status'] === '0' || $web['status'] === 0 ||
$web['status'] === 0.0 || $web['status']) {
// not empty: use the value
} else {
// consider it as empty, since status may be FALSE, null or an empty string
}
}
The generic condition ($web['status']) should be left at the end of the entire statement.
property_exists, isset, array_key_exists and empty shows that isset always detects if the variable has been assigned a non-null value and array_key_exists always detects if the key is accessible.isset && !empty is redundant. Just !empty will do exactly the same.empty does seem to absorb/suppress all notices/errors, avoiding the "Undefined offset/index" notice to be thrown due to a non-existing key in the array (even in PHP v4.4.9, just tested :). I adjusted the answer, thanks for pointing that out!You're using isset, what isset does is check if the variable is set ('exists') and is not NULL. What you're looking for is empty, which checks if a variable is empty or not, even if it's set. To check what is empty and what is not take a look at:
http://php.net/manual/en/function.empty.php
Also check http://php.net/manual/en/function.isset.php for what isset does exactly, so you understand why it doesn't do what you expect it to do.
$e = 0; echo empty($e) will return false too. It does not matter in what format we provide the number. (String, Float, int) See: php.net/manual/en/…if(!empty($web))
{
echo 'Something';
}
if($var !== '' && $var !== NULL)
{
echo $var;
}
empty. Deceze is very careful to explain that his check is "truthy". If the OP specifically expects a boolean false value, that is not clear in the question. Your unexplained answer does not speak of allowing boolean false values.the_field() return false AND would the OP want to handle it as a non-empty outcome if it does? I reckon not.Your problem is in your use of the_field(), which is for Advanced Custom Fields, a wordpress plugin.
If you want to use a field in a variable you have to use this: $web = get_field('website');.
i hope this will work too, try using"is_null"
<?php
$web = the_field('website');
if (!is_null($web)) {
?>
....html code here
<?php
} else {
echo "Niente";
}
?>
http://php.net/manual/en/function.is-null.php
hope that suits you..
