另一个条件运算符是"?:"(或三元)运算符 。 赋默认值 <?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'; }...
-2 0 php?: // Example usage for: Ternary Operator $action = $_POST['action'] ?: 'default'; // The above is identical to this if/else statement if (empty($_POST['action'])) { $action = 'default'; } else { $action = $_POST['action']; }类似页面 带有示例的类似页面 ...
For example:<?phpclass A{ public function __get($property) { echo 'Called __get for ' . $property . PHP_EOL; }}$a = new A();echo 'Trying null coalescing operator' . PHP_EOL;$b = $a->test ?? 5;echo 'Trying isset()' . PHP_EOL;if (isset($a->test)) {$b = $a->...
OperatorNameExampleResultTry it ?: Ternary $x = expr1 ? expr2 : expr3 Returns the value of $x.The value of $x is expr2 if expr1 = TRUE.The value of $x is expr3 if expr1 = FALSE Try it » ?? Null coalescing $x = expr1 ?? expr2 Returns the value of $x.The value of...
$txt1Array operator: Union (+)Array operator: Equality (==)Array operator: Identity (===)Array operator: Inequality (!=)Array operator: Inequality (<>)Array operator: Non-identity (!==)Conditional assignment operator: Ternary (?:)Conditional assignment: Null coalescing (??)...
$a='Multi-line example'// concatenation operator (.) ."\n"// indenting new lines .'of what to do'; String types String types are a constant feature within the PHP community, but hopefully this section will explain the differences between the string types and their benefits/uses. ...
ExampleRun this code » <?php if($age < 18){ echo 'Child'; // Display Child if age is less than 18 } else{ echo 'Adult'; // Display Adult if age is greater than or equal to 18 } ?>Using the ternary operator the same code could be written in a more compact way:...
有三种操作符因为太复杂,需要在单独的章节中进行讲解。第一个就是三元操作符。它被叫做三元操作符是因为它有三个操作数:一个条件,条件为真的结果,条件为假的结果。感觉是不是有点像if条件判断?答对了,这就是if条件判断的一种缩略形式。下面有个例子: <?php $agestr = ($age < 16) ? 'child' : 'adult...
OperatorNameExampleLong EquivalentDescription = Assignment $x = $y $x = $y $x is set to the value of $y += Addition $x += $y $x = $x + $y $y will be added to $x -= Subtraction $x -= $y $x = $x - $y $x is subtracted by $y *= Multiplication $x *= $y $x ...
$value->bindTo($this, $this): $value; //Assignment using ternary operator.}}abstract class MBR_ATTR{//A class full of attributes that objects can take on; abstract since not to be instantiated (If I could make it "final" as well, I would).public static function is_a_walker(iface_...