What does this statement means (<?=) in a tenary operator

[asker54]

I met with the ternary operator statement

 

<p>Values <?= $_POST['submitted'] ? "sorted by {$sortType}" : "unsorted"; ?>:</p>

 

I do understand what the statement mean except the the equality sign after the question mark. I would appreciate it if any one would explain what did it mean.

 

Thanks

[kicken]

<?= is just a shortcut way of saying <?php echo, so that line is equal to:

<?php echo $_POST['submitted'] ? "sorted by {$sortType}" : "unsorted"; ?>

It will echo 'sorted by $sortType' if the post variable exists, otherwise it will echo 'unsorted'.

[Ch0cu3r]

Do note though that the <?= ?> tags will only work if short_open_tag directive is enabled in the php.ini file. Not all servers will have this setting enabled and/or allowed to be changed. Using full PHP tag syntax is recommend (as kicken showed you above).

[kicken]

Do note though that the <?= ?> tags will only work if short_open_tag directive is enabled in the php.ini file.

Also note that the above is only true in <5.4. In 5.4.0 and newer, <?= will always work and is no longer tied to short tags.

[asker54]

@kicken @Ch0cu3r

 

I also thought like yours, but when I substitute <?= with <?php echo , I get the error

 

Values
Notice: Undefined index: submitted in C:\wamp\www\general\sortingarray.php on line 46
unsorted:

 

and when I leave it as it is, I get no error.

 

Here is the code I am applying:

<?php
function userSort($a, $b)
{
// smarts is all-important, so sort it first
if ($b == "smarts") {
return 1;
}
else if ($a == "smarts") {
return −1;
}
return ($a == $b) ? 0 : (($a < $b) ? −1 : 1);
}
$values = array(
'name' => "Buzz Lightyear",
'email_address' => "[email protected]",
'age' => 32,
'smarts' => "some"
);
if ($_POST['submitted']) {
$sortType = $_POST['sort_type'];
if ($sortType == "usort" || $sortType == "uksort" || $sortType == "uasort") {
$sortType($values, "user_sort");
}
else {
$sortType($values);
}
} ?>
<form action="<?php echo $_SERVER['PHP_SELF']; ?> " method="post">

<p>
<input type="radio" name="sort_type"
value="sort" checked="checked" /> Standard<br />
<input type="radio" name="sort_type" value="rsort" /> Reverse<br />
<input type="radio" name="sort_type" value="usort" /> User-defined<br />
<input type="radio" name="sort_type" value="ksort" /> Key<br />
<input type="radio" name="sort_type" value="krsort" /> Reverse key<br />
<input type="radio" name="sort_type"
value="uksort" /> User-defined key<br />
<input type="radio" name="sort_type" value="asort" /> Value<br />
<input type="radio" name="sort_type"
value="arsort" /> Reverse value<br />
<input type="radio" name="sort_type"
value="uasort" /> User-defined value<br />
</p>
<p align="center"><input type="submit" value="Sort" name="submitted" /></p>
<p>Values <?php echo $_POST['submitted'] ? "sorted by {$sortType}" : "unsorted"; ?>:</p>
<ul>
<?php foreach ($values as $key => $value) {
echo "<li><b>{$key}</b>: {$value}</li>";
} ?>
</ul>
</form>

Thanks

 

 

 

 

[trq]

That is a different issue. Your not checking to see that $_POST['submitted'] exists.

 

<?php echo isset($_POST['submitted']) ? "sorted by {$sortType}" : "unsorted"; ?>

[mac_gyver]

it's likely your version/configuration of php isn't recognizing the <? at all and that specific line of code wasn't being seen as being php code. when you change to the full opening <?php tag, it's now being seen as php code.

 

the correct way of testing a variable that might not exist is to use isset()

 

edit: lol, the forum's pop up about posts being made came after i hit the submit button and listed 2 new posts having been made, trq's and mine.

[asker54]

@ trq

 

Thanks. I replaced the the (

 

 

@kicken @Ch0cu3r

 

I also thought like yours, but when I substitute <?= with <?php echo , I get the error

 

Values
Notice: Undefined index: submitted in C:\wamp\www\general\sortingarray.php on line 46
unsorted:

 

and when I leave it as it is, I get no error.

 

Here is the code I am applying:

<?php
function userSort($a, $b)
{
// smarts is all-important, so sort it first
if ($b == "smarts") {
return 1;
}
else if ($a == "smarts") {
return −1;
}
return ($a == $b) ? 0 : (($a < $b) ? −1 : 1);
}
$values = array(
'name' => "Buzz Lightyear",
'email_address' => "[email protected]",
'age' => 32,
'smarts' => "some"
);
if ($_POST['submitted']) {
$sortType = $_POST['sort_type'];
if ($sortType == "usort" || $sortType == "uksort" || $sortType == "uasort") {
$sortType($values, "user_sort");
}
else {
$sortType($values);
}
} ?>
<form action="<?php echo $_SERVER['PHP_SELF']; ?> " method="post">

<p>
<input type="radio" name="sort_type"
value="sort" checked="checked" /> Standard<br />
<input type="radio" name="sort_type" value="rsort" /> Reverse<br />
<input type="radio" name="sort_type" value="usort" /> User-defined<br />
<input type="radio" name="sort_type" value="ksort" /> Key<br />
<input type="radio" name="sort_type" value="krsort" /> Reverse key<br />
<input type="radio" name="sort_type"
value="uksort" /> User-defined key<br />
<input type="radio" name="sort_type" value="asort" /> Value<br />
<input type="radio" name="sort_type"
value="arsort" /> Reverse value<br />
<input type="radio" name="sort_type"
value="uasort" /> User-defined value<br />
</p>
<p align="center"><input type="submit" value="Sort" name="submitted" /></p>
<p>Values <?= $_POST['submitted'] ? "sorted by {$sortType}" : "unsorted"; ?>:</p>
<ul>
<?php foreach ($values as $key => $value) {
echo "<li><b>{$key}</b>: {$value}</li>";
} ?>
</ul>
</form>

Thanks @trq. please see the above quoted text where I replaced the equqlity sign (=) in the original program above with your suggested replacement

<p>Values <?php echo isset($_POST['submitted']) ? "sorted by {$sortType}" : "unsorted"; ?>:</p>

The statement that I changed in the above quoted program is:

<p>Values <?= $_POST['submitted'] ? "sorted by {$sortType}" : "unsorted"; ?>:</p>

With both settings, the code works without errors. What I do not understand what does the equality sign represent here, does it equal the isset function here.

 

 

 

 

 

 

 

 

[Ch0cu3r]

 

 

With both settings, the code works without errors. What I do not understand what does the equality sign represent here, does it equal the isset function here.

 

No the = in the <?= tags is not the same as the assignment operator. It is just short hand syntax for <?php echo

 

The isset

isset($_POST['submitted']) ? "sorted by {$sortType}" : "unsorted"; 

The above Is returning the string "sorted by {$sortType}" if $_POST['submmited'] exists. If it doesn't exist the string "unsorted" is returned. The <?= tag will echo out the string returned.

[asker54]

Ch0cu3r

Thanks. Can you please tell me where can I read about that <?= is equivalent to the syntax <?php echo

[kicken]

Ch0cu3r

Thanks. Can you please tell me where can I read about that <?= is equivalent to the syntax <?php echo

It's in the manual: Language Reference: PHP Tags: Escaping HTML

[asker54]

It's in the manual: Language Reference: PHP Tags: Escaping HTML

Many thanks