我在哪里可以找到这方面的文档？

Question

我在哪里可以找到以下代码的文档？

$a = .01 * rand(0, 100) >= .5; //I don't need doc for this line, its for generating a random boolean! 
$b = "it was true!"; 
$c = "it was false!"; 

echo "Guess what, " . ($a ? $b : $c); // I need documentation for how this works! 

http://viper-7.com/H8upUh

Answer 1

这是ternary operator，这是巩固一个简单if/else表达方式。

从文档：

// 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']; 
}