简单介绍一下PHP 5.4的新特性

1. 实例化时访问类成员

class Human{
	function __construct($name){
		$this->name = $name;
	}
	public function hello(){
		return "Hi " . $this->name;
	}
}
// old style
$human = new Human("ixcv");
echo $human->hello();

// new cool style
echo (new Human("ixcv"))->hello();

2. 短数组定义语法

$a = [1, 2, 3];
print_r($a);

3. 支持 Class::{expr}() 语法

foreach ([new Human("ixcv"), new Human("Peter")] as $human)
	echo $human->{'hello'}();
}

4. 通过数组间接调用方法

$f = [new Human("ixcv"), 'hello'];
echo $f();

5. Callable typehint

function hi(callable $f) {
	$f();
}
hi([new Human("ixcv"), 'hello']);

6. Traits

trait FlyMutant {
	public function fly() {
		return 'I can fly!';
	}
}

class Mutant extends Human {
	use FlyMutant;
}
$mutant = new Mutant("Storm");
echo $mutant->fly();

7. 支持数组提领(Array dereferencing support)

function data() {
	return ['name' => 'ixcv', 'surname' => 'Ayuso'];
}
echo data()['name'];