where can i learn about using ? : in my true or false code

[ricky spires]

i keep seeing people use this kind of code but i cant find any document or help web pages on it. im sure there is but i done know what to call it.

 

i would really like to learn more about it

 

for example

$lang  = isset($_GET['lang']) ? (int)$_GET['lang'] : 1;

 

or

return !empty($result_array) ? array_shift($result_array) : false;

 

 

 

[Maq]

It's called a ternary operator.  Search for it here:

http://php.net/manual/en/language.operators.comparison.php

[ricky spires]

thanks

 

this is a perfect example

 

<?php
// Example usage for: Ternary Operator
$action = (empty($_POST['action'])) ? 'default' : $_POST['action'];

// The above is identical to this if/else statement
if (empty($_POST['action'])) {
    $action = 'default';
} else {
    $action = $_POST['action'];
}

?>

[scootstah]

You don't actually need the surrounding ( )'s.

 

This will work fine:

$action = empty($_POST['action']) ? 'default' : $_POST['action'];

[Andy-H]

Although you do need to wrap the whole statement in parentheses if you want to concatenate the returned value -

 

 

$string = 'Testing ternary: '. (true ? 'true' : 'false');

[jcbones]

I always wrap the conditional in ()'s for readability.  But, then again, most people think I am strange...

[Pikachu2000]

In most cases, I assign the value to a variable anyhow, then use the variable in the string. More readable (to me, anyhow) that way.

 

echo "<select name=\"box\">\n";
foreach( $array as $k => $v ) {
     $selected = $k == $_POST['box'] ? 'selected="selected"' : '';
     echo "<option value=\"$k\" $selected>$v</option>\n";
}
echo "</select>\n"

;