从PHP5到PHP7

<?php
// PHP 5 era code that will break.
function handler(Exception $e) { ... }
set_exception_handler('handler');

// PHP 5 and 7 compatible.
function handler($e) { ... }

// PHP 7 only.
function handler(Throwable $e) { ... }

try{
    ...
} catch(\Exception $e) {    //这里要注意是Exception or Error or Throwable
    ...
}

<?php

error_reporting(E_ALL|E_STRICT);

class MyTest{
    function func(){
        echo "none static";
    }

}

//PHP 5.x : Strict Standards: Non-static method MyTest::func() ...
//PHP 7.X : Deprecated: Non-static method MyTest::func() ...
MyTest::func();

<?php
    list($a[], $a[], $a[]) = [1, 2, 3];
    var_dump($a);

<?php
    list() = $a;
    list(,,) = $a;
    list($x, list(), $y) = $a;

<?php
    $str = 'abcde';
    list($a, $b) = $str;
    var_dump(array($a, $b));

<?php
    $array = [];
    $array["a"] =& $array["b"];
    $array["b"] = 1;
    var_dump($array);

array(2) {
  ["b"]=>
  &int(1)
  ["a"]=>
  &int(1)
}

array(2) {
  ["a"]=>
  &int(1)
  ["b"]=>
  &int(1)
}

<?php
function f() {
    // Valid in PHP 5 only.
    global $$foo->bar;

    // Valid in PHP 5 and 7.
    global ${$foo->bar};
}

<?php

error_reporting(E_ALL|E_STRICT);

function param() {
    return array(1, 2, 3);
}

function test(&$a) {
    var_export($a);
}

//PHP5 : Strict Standards: Only variables should be passed by reference in...
//PHP7 : Notice: Only variables should be passed by reference in ...
test(param());

//PHP5 : NO ERROR
//PHP7 : Notice: Only variables should be passed by reference in ...
test((param()));

<?php
$array = [0, 1, 2];
foreach ($array as &$val) {
    var_dump(current($array));
}

<?php

$arr = array(
    'a' => 1,
);

foreach ($arr as $key => &$item) {
    echo $key."\n";
    $arr['b'] = 2;
}

unset($item);

<?php

//PHP5 : 非法8进制数字会进行转换，$a = 01
//PHP7 : Parse error: Invalid numeric literal in ...
$a = 0187;

<?php
//PHP5 : echo int(0)
//PHP7 : Fatal error: Uncaught ArithmeticError: Bit shift by negative number in...
var_dump(1 >> -1);

<?php

//PHP5 : Warning: Division by zero in ..., return false
//PHP7 : Warning: Division by zero in ..., return NAN
echo (0/0)."\n";

//PHP5 : Warning: Division by zero in ..., return false
//PHP7 : Warning: Division by zero in ..., return INF
echo (3/0)."\n";

//PHP5 : Warning: Division by zero in ..., return false
//PHP7 : Fatal error: Uncaught DivisionByZeroError: Modulo by zero in ...
echo (0%0)."\n";

<?php
    //PHP5 : bool(true)
    //PHP7 : bool(false)
    var_dump("0x123" == "291");
    //PHP5 : bool(true)
    //PHP7 : bool(false)
    var_dump(is_numeric("0x123"));
    //PHP5 : int(15)
    //PHP7 : int(0)
    var_dump("0xe" + "0x1");
    //PHP5 : string(2) "oo"
    //PHP7 : Notice: A non well formed numeric value encountered in ...
    var_dump(substr("foo", "0x1"));

<?php
echo "\u{9999}\n";
echo "\u{0009999}\n";
echo "\u{测试文本";

<?php
class C {}

//PHP7 : Parse error: syntax error, unexpected 'new' (T_NEW) in
$c =& new C;

//It's OK
$a = new C;
$c =& $a;

<?php
class A {
    public function test() { var_dump($this); }
}

// Note: Does NOT extend A
class B {
    public function callNonStaticMethodOfA() { A::test(); }
}

(new B)->callNonStaticMethodOfA();

<?php
echo yield -1;
// Was previously interpreted as
echo (yield) - 1;
// And is now interpreted as
echo yield (-1);

yield $foo or die;
// Was previously interpreted as
yield ($foo or die);
// And is now interpreted as
(yield $foo) or die;

<?php
//PHP7 : Fatal error: Redefinition of parameter $b in ...
function test($a, $b, $b) {

}

<?php

//PHP7 : Fatal error: Switch statements may only contain one default clause in ...
switch (1) {
    case 1:
    break;
    default:
    break;
    default:
    break;
}

<?php

error_reporting(E_ALL|E_STRICT);

function a($a, $b){
    $a = 11;
    var_export(func_get_args());
}

a(12,12);