PHP7の新機能の紹介

$$foo['bar']['baz']//PHP5($$foo)[‘bar’]['baz']//PHP7: 遵循从左到右的原则${$foo[‘bar’]['baz']}

//PHP5$a =  array(1, 2, 3);foreach ($a as $v){var_dump(current($a));}int(2)int(2)int(2)$a =  array(1, 2, 3);$b=&$a;foreach ($a as $v){var_dump(current($a));}int(2)int(3)bool(false)$a =  array(1, 2, 3);$b=$a;foreach ($a as $v){var_dump(current($a));}int(1)int(1)int(1)//PHP7：不再操作数据的内部指针了$a =  array(1, 2, 3);foreach ($a as $v){var_dump(current($a))}int(1)int(1)int(1)$a =  array(1, 2, 3);$b=&$a;foreach ($a as $v){var_dump(current($a))int(1)int(1)int(1)$a =  array(1, 2, 3);$b=$a;foreach ($a as $v){var_dump(current($a))}int(1)int(1)int(1)

//<=> - 比较两个数的大小【-1：前者小于后者，0：前者等于后者，1：前者大于后者】echo 1 <=> 2;//-1echo 1 <=> 1;//0echo 1 <=> 0;//1// ** - 【a的b次方】echo 2 ** 3;//8//?? - 三元运算符的改进//php5$_GET['name'] ? $_GET['name'] : '';//Notice: Undefined index: …//php7$_GET['name'] ?? '' -> '';//\u{xxxx} - Unicode字符的解析echo "\u{4f60}";//你echo "\u{65b0}";//新

function getInt() : int {    return “test”;}; getInt();//PHP5#PHP Parse error:  parse error, expecting `’{‘’…//PHP7#Fatal error:Uncaught TypeError: Return value of getInt() must be of the type integer, string returned 

function getInt(int $num) : int {    return $num;}; getInt(“test”);//PHP5#PHP Catchable fatal error:  Argument 1 passed to getInt() must be an instance of int, string given…//PHP7#Fatal error: Uncaught TypeError: Argument 1 passed to getInt() must be of the type integer, string given…

try {    non_exists_func();} catch(EngineException $e) {echo “Exception: {$e->getMessage();}\n”;}//这里用php7试了一下还是没法捕获，但是看鸟哥介绍说是可行的。。。#Exception: Call to undefined function non_exists_func()

//PHP5class Collection {public function foreach($arr) {}}#Parse error:  parse error, expecting `"identifier (T_STRING)”’...//PHP7class Collection {    public function foreach($arr) {}    public function in($arr){}    public function where($condition){}    public function order($condition){}}$collection = new Collection();$collection->where()->in()->foreach()->order();