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1. null coalescing operator (??)
??Syntax: If the variable exists and the value is not NULL, it will return its own value, otherwise it will return its second operand.
1 //php7以前
if判断
2 if(empty($_GET['param'])) {
3 $param = 1;
4 }else{
5 $param = $_GET['param'];
6 } 7
8 //php7以前 三元运算符
9 $param = empty($_GET['param']) ? 1 : $_GET['param'];10
11 //PHP7 null合并运算符12 $param = $_GET['param'] ?? 1;//1 2. define() defines a constant array
1 //php7以前
2 define("CONTENT", "hello world");
3 echo CONTENT;//hello world 4
5 //PHP7 6 define('ANIMALS', [
7 'dog',
8 'cat',
9 'bird'
10 ]);
11 echo ANIMALS[2];//bird12
13 //PHP7 类外也可使用const来定义常量
14 const CONSTANT = 'Hello World';
15 echo CONSTANT;//Hello World
3. Combined comparison operators (< =>)
##The combined comparison operator is used to compare two expressions. It returns when $a is less than, equal to, or greater than $b respectively. -1, 0 or 1. The comparison principle is based on the general comparison rules of PHP. 1 //整数
2 echo 1 <=> 1; // 0
3 echo 1 <=> 2; // -1
4 echo 2 <=> 1; // 1 5
6 //浮点数 7 echo 1.5 <=> 1.5; // 0
8 echo 1.5 <=> 2.5; // -1
9 echo 2.5 <=> 1.5; // 1
11 //字符串12 echo "a" <=> "a"; // 0
13 echo "a" <=> "b"; // -1
14 echo "b" <=> "a"; // 1
4. Variable type declaration
Two modes: forced (default) and strict mode. The following type parameters can be used: string, int, float, bool 1 //... 操作符: 表示这是一个可变参数. php5.6及以上的版本可使用: 函数定义的时候变量前使用.
2 function intSum(int ...$ints){
3 return array_sum($ints);
4 }
5 var_dump(intSum(2,'3.5'));//5
6
7 //严格模式
8 //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
9 declare(strict_types=1);
10 function add(int $a,int $b){
11 return $a+$b;
12 }
13 var_dump(add(2,'3.5')); //Fatal error: Uncaught TypeError: Argument 2 passed to add() must be of the type integer
5. Return value type declaration
Add support for return type declaration. Similar to parameter type declaration. (For usage, add: type name after the function definition)1 //有效的返回类型
2 declare(strict_types = 1);
3 function getInt(int $value): int {
4 return $value;
5 }
6 print(getInt(6));//6
1 //无效返回类型
2 declare(strict_types = 1);
3 function getNoInt(int $value): int {
4 return $value+'2.5';
5 }
6 print(getNoInt(6));//Fatal error: Uncaught TypeError: Return value of getNoInt() must be of the type integer
6. Anonymous class
Allows new class {} to create an anonymous object. 1 <?php
2 //php7以前 接口实现
3 interface User{
4 public function getDiscount();
5 }
6 class VipUser implements User{
7 //折扣系数
8 private $discount = 0.6;
9 public function getDiscount() {
10 return $this->discount;
11 }
12 }
13 class Goods{
14 private $price = 200;
15 private $objectVipUser;
16 //User接口VipUser类实现
17 public function getUserData($User){
18 $this->objectVipUser = $User;
19 $discount = $this->objectVipUser->getDiscount();
20 echo "商品价格:".$this->price*$discount;
21 }
22 }
23 $display = new Goods();
24 //常规实例化接口实现对象
25 $display ->getUserData(new VipUser);//商品价格:120
1 <?php
2 //php7 创建一个匿名的对象
3 interface User{
4 public function getDiscount();
5 }
6 class Goods{
7 private $price = 200;
8 private $objectVipUser;
9 public function getUserData($User){
10 $this->objectVipUser = $User;
11 $discount = $this->objectVipUser->getDiscount();
12 echo "商品价格:".$this->price*$discount;
13 }
14 }
15 $display = new Goods();
16 //new匿名对象实现user接口
17 $display ->getUserData(new class implements User{
18 private $discount = 0.6;
19 public function getDiscount() {
20 return $this->discount;
21 }
22 });//商品价格:120
7. Closure::call()
The Closure::call() method was added as a short way to temporarily bind a Scope the object to a closure and call it. Compared to PHP5's bindTo, its performance is much faster. 1 <?php
2 //php7以前
3 class A {
4 private $attribute = 'hello world';
5 }
6
7 $getClosure = function(){
8 return $this->attribute;
9 };
10
11 $getAttribute = $getClosure->bindTo(new A, 'A');//中间层闭包
12 echo $getAttribute();//hello world
1 <?php
2 //PHP7
3 class A {
4 private $attribute = 'hello world';
5 }
6
7 $getClosure = function(){
8 return $this->attribute;
9 };
10
11 echo $getClosure->call(new A);//hello world
8. unserialize()
unserialize() function: The filtering feature can prevent code injection of illegal data and provide safer deserialized data 1 <?php
2 class A{
3 public $name = 'admin_a';
4 }
5 class B{
6 public $name = 'admin_b';
7 }
8 9 $objA = new A();
10 $objB = new B();
11 12 $serializedObjA = serialize($objA);
13 $serializedObjB = serialize($objB);
14 15 16 //默认行为是接收所有类; 第二个参数可以忽略17 $dataA = unserialize($serializedObjA , ["allowed_classes" => true]);
18 var_dump($dataA);//object(A)#3 (1) { ["name"]=> string(7) "admin_a" }19 20 //如果allowed_classes设置为false,unserialize会将所有对象转换为__PHP_Incomplete_Class对象 21 $dataA = unserialize($serializedObjA , ["allowed_classes" => false]);
22 var_dump($dataA);//object(__PHP_Incomplete_Class)#4 (2) { ["__PHP_Incomplete_Class_Name"]=> string(1) "A" ["name"]=> string(7) "admin_a" }23 24 //转换所有对象到 __PHP_Incomplete_Class对象，除了对象"B"25 $dataB = unserialize($serializedObjB , ["allowed_classes" => ["B"]]);
26 var_dump($dataB);//object(B)#3 (1) { ["name"]=> string(7) "admin_b" }
9. IntlChar
##IntlChar: Provides some Access to utility methods for accessing Unicode character information. NOTE: The Intl extension must be installed to use!1 var_dump(IntlChar::CODEPOINT_MAX);//int(1114111)
2 echo '<br>';
3 var_dump(IntlChar::charName('+'));//string(9) "PLUS SIGN"
4 echo '<br>';
5 var_dump(IntlChar::ispunct('?'));//bool(true)
The CSPRNG function provides a simple mechanism to generate cryptographic random numbers.
random_bytes() - Cryptographically protected pseudo-random string.
random_int() - Cryptographically protected pseudo-random integer.
1 $bytes = random_bytes(8); 2 echo(bin2hex($bytes));//随机2073a110a2e3c497 3 echo '<br>'; 4 echo(random_int(1, 999));//随机786 5 echo '<br>'; 6 print(random_int(-999, -1));//随机-35711. use statement
You can use a single use statement to import classes, functions and constants from the same namespace instead of using multiple use statements.
1 //PHP7之前
2 use some\namespace\ClassA;
3 use some\namespace\ClassB;
4 use some\namespace\ClassC as C;
5 use function some\namespace\fn_a;
6 use function some\namespace\fn_b;
7 use function some\namespace\fn_c;
8 use const some\namespace\ConstA;
9 use const some\namespace\ConstB;
10 use const some\namespace\ConstC;
11
12 // PHP7之后
13 use some\namespace\{ClassA, ClassB, ClassC as C};
14 use function some\namespace\{fn_a, fn_b, fn_c};
15 use const some\namespace\{ConstA, ConstB, ConstC};
12. intpThe newly added intp() function receives two parameters, and the return value is the value of the first parameter divided by the second parameter and rounded
.1 echo intp(8,4);//2
2 echo intp(10,4);//2
3 echo intp(5,10);//0
PHP7 改变了大多数错误的报告方式.不同于PHP5的传统错误报告机制,现在大多数错误被作为Error异常抛出.
这种Error异常可以像普通异常一样被try / catch块所捕获. 如果没有匹配的try / catch块,则调用异常处理函数（由 set_exception_handler() 注册）进行处理.
如果尚未注册异常处理函数,则按照传统方式处理：被报告为一个致命错误（Fatal Error）.
Error类并不是从Exception类扩展出来的,所以用catch (Exception $e) { ... } 这样的代码是捕获不到Error的.你可以用 catch (Error $e) { ... } 这样的代码，
或者通过注册异常处理函数（ set_exception_handler()）来捕获Error.
1 <?php
2 //php7以前 自定义异常处理
3 class getException extends Exception{
4 public function errorMsg(){
5 return '错误的信息'.$this->getMessage().'<br>错误的代码'.$this->getCode();
6 }
7 }
8
9 try {
10 $num =10;
11 if($num > 1) {
12 throw new getException($num,404);
13 }
14 } catch (getException $e) {
15 echo $e->errorMsg();
16 }
1 <?php
2 //php7 异常处理
3 try {
4 test();
5 }catch(Error $e) {
6 echo $e->getMessage();//Call to undefined function test()
7 }The above is the detailed content of Understand and compare new features of php7. For more information, please follow other related articles on the PHP Chinese website!