php7新特性的理解和比较总结

//php7以前 if判断 

if(empty($_GET['param'])) { 

  $param = 1; 

}else{ 

 $param = $_GET['param']; 

} 

 

//php7以前 三元运算符 

$param = empty($_GET['param']) ? 1 : $_GET['param'];

 

//PHP7 null合并运算符

 

 $param = $_GET['param'] ?? 1;//1

//php7以前 

 define("CONTENT", "hello world"); 

 echo CONTENT;//hello world 

 

 //PHP7 

 define('ANIMALS', [ 

 'dog', 

  'cat', 

 'bird'

]);

 echo ANIMALS[2];//bird

 

 //PHP7 类外也可使用const来定义常量

 const CONSTANT = 'Hello World'; 

 echo CONSTANT;//Hello World

/整数 

echo 1 => 1; // 0 

echo 1 => 2; // -1 

echo 2 => 1; // 1 

 

 //浮点数 

echo 1.5 => 1.5; // 0 

echo 1.5 => 2.5; // -1 

echo 2.5 => 1.5; // 1

 

 //字符串

echo "a" => "a"; // 0

echo "a" => "b"; // -1

echo "b" => "a"; // 1

//... 操作符: 表示这是一个可变参数. php5.6及以上的版本可使用: 函数定义的时候变量前使用. 

 function intSum(int ...$ints){ 

 return array_sum($ints); 

 } 

var_dump(intSum(2,'3.5'));//5 

 

 //严格模式 

 //模式声明：declare(strict_types=1); 默认情况值为0，值为1代表为严格校验的模式 

 declare(strict_types=1);

 function add(int $a,int $b){

  return $a+$b;

 }

 var_dump(add(2,'3.5')); //Fatal error: Uncaught TypeError: Argument 2 passed to add() must be of the type integer

//有效的返回类型

declare(strict_types = 1);

 function getInt(int $value): int {

 return $value;

 }

 print(getInt(6));//6

//无效返回类型

declare(strict_types = 1);

 function getNoInt(int $value): int {

 return $value+'2.5';

 }

 print(getNoInt(6));//Fatal error: Uncaught TypeError: Return value of getNoInt() must be of the type integer

?php 

//php7以前 接口实现 

interface User{ 

 public function getDiscount(); 

} 

class VipUser implements User{ 

 //折扣系数 

 private $discount = 0.6; 

 public function getDiscount() {

  return $this->discount;

 }

}

class Goods{

 private $price = 200;

 private $objectVipUser;

 //User接口VipUser类实现

 public function getUserData($User){

  $this->objectVipUser = $User;

  $discount = $this->objectVipUser->getDiscount();

  echo "商品价格:".$this->price*$discount;

 }

}

$display = new Goods();

//常规实例化接口实现对象

$display ->getUserData(new VipUser);//商品价格:120

?php 

//php7 创建一个匿名的对象 

interface User{ 

 public function getDiscount(); 

} 

class Goods{ 

 private $price = 200; 

 private $objectVipUser; 

 public function getUserData($User){

  $this->objectVipUser = $User;

  $discount = $this->objectVipUser->getDiscount();

  echo "商品价格:".$this->price*$discount;

 }

}

$display = new Goods();

//new匿名对象实现user接口

$display ->getUserData(new class implements User{

 private $discount = 0.6;

 public function getDiscount() {

  return $this->discount;

 }

});//商品价格:120

?php 

//php7以前 

class A { 

 private $attribute = 'hello world'; 

} 

 

$getClosure = function(){ 

 return $this->attribute; 

};

 

$getAttribute = $getClosure->bindTo(new A, 'A');//中间层闭包

echo $getAttribute();//hello world

?php 

//PHP7 

class A { 

 private $attribute = 'hello world'; 

} 

 

$getClosure = function(){ 

 return $this->attribute; 

};

 

echo $getClosure->call(new A);//hello world

?php 

 class A{ 

  public $name = 'admin_a'; 

 } 

 class B{ 

  public $name = 'admin_b'; 

 } 

 $objA = new A(); 

 $objB = new B(); 

 $serializedObjA = serialize($objA); 

 $serializedObjB = serialize($objB); 

 //默认行为是接收所有类; 第二个参数可以忽略

 $dataA = unserialize($serializedObjA , ["allowed_classes" => true]); 

 var_dump($dataA);//object(A)#3 (1) { ["name"]=> string(7) "admin_a" }

//如果allowed_classes设置为false,unserialize会将所有对象转换为__PHP_Incomplete_Class对象 

 $dataA = unserialize($serializedObjA , ["allowed_classes" => false]); 

 var_dump($dataA);//object(__PHP_Incomplete_Class)#4 (2) { ["__PHP_Incomplete_Class_Name"]=> string(1) "A" ["name"]=> string(7) "admin_a" }

//转换所有对象到 __PHP_Incomplete_Class对象，除了对象"B"

 $dataB = unserialize($serializedObjB , ["allowed_classes" => ["B"]]); 

var_dump($dataB);//object(B)#3 (1) { ["name"]=> string(7) "admin_b" }

var_dump(IntlChar::CODEPOINT_MAX);//int(1114111) 

echo 'br>';

var_dump(IntlChar::charName('+'));//string(9) "PLUS SIGN" 

echo 'br>';

var_dump(IntlChar::ispunct('?'));//bool(true)

$bytes = random_bytes(8); 

echo(bin2hex($bytes));//随机2073a110a2e3c497

echo 'br>';

echo(random_int(1, 999));//随机786

echo 'br>';

print(random_int(-999, -1));//随机-357

//PHP7之前 

use some\namespace\ClassA; 

use some\namespace\ClassB; 

use some\namespace\ClassC as C; 

use function some\namespace\fn_a;

use function some\namespace\fn_b; 

use function some\namespace\fn_c; 

use const some\namespace\ConstA; 

use const some\namespace\ConstB;

use const some\namespace\ConstC;

// PHP7之后

use some\namespace\{ClassA, ClassB, ClassC as C};

use function some\namespace\{fn_a, fn_b, fn_c};

use const some\namespace\{ConstA, ConstB, ConstC};

echo intp(8,4);//2

echo intp(10,4);//2

echo intp(5,10);//0

?php 

//php7以前 自定义异常处理 

class getException extends Exception{ 

 public function errorMsg(){ 

  return '错误的信息'.$this->getMessage().'br>错误的代码'.$this->getCode(); 

 } 

} 

 

try {

 $num =10;

 if($num > 1) {

  throw new getException($num,404);

 }

} catch (getException $e) {

 echo $e->errorMsg();

 }

?php 

//php7 异常处理

try {

 test();

}catch(Error $e) {

 echo $e->getMessage();//Call to undefined function test()

  }