エキサイティングな PHP7.4

  function test(...$args) { var_dump($args); }
  test(1, 2, 3);

  $arr = [...$args];

   $parts = ['apple', 'pear'];
  $fruits = ['banana', 'orange', ...$parts, 'watermelon'];
  var_dump($fruits);

Parse error: syntax error, unexpected '...' (T_ELLIPSIS), expecting ']' in /app/spread-operator.php on line 3

array(5) {
    [0]=>
    string(6) "banana"
    [1]=>
    string(6) "orange"
    [2]=>
    string(5) "apple"
    [3]=>
    string(4) "pear"
    [4]=>
    string(10) "watermelon"
  }

$arr1 = [1, 2, 3];
  $arr2 = [4, 5, 6];
  $arr3 = [...$arr1, ...$arr2];
  $arr4 = [...$arr1, ...$arr3, 7, 8, 9];

function buildArray(){
    return ['red', 'green', 'blue'];
  }
  $arr1 = [...buildArray(), 'pink', 'violet', 'yellow'];

array(6) {
    [0]=>
    string(3) "red"
    [1]=>
    string(5) "green"
    [2]=>
    string(4) "blue"
    [3]=>
    string(4) "pink"
    [4]=>
    string(6) "violet"
    [5]=>
    string(6) "yellow"
  }

function generator() {
    for ($i = 3; $i <= 5; $i++) {
        yield $i;
    }
  }
  $arr1 = [0, 1, 2, ...generator()];

$arr1 = ['red', 'green', 'blue'];
  $arr2 = [...&$arr1];

Parse error: syntax error, unexpected '&' in /app/spread-operator.php on line 3

   $arr0 = 'red';
  $arr1 = [&$arr0, 'green', 'blue'];
  $arr2 = ['white', ...$arr1, 'black'];

array(5) {
    [0]=>
    string(5) "white"
    [1]=>
    &string(3) "red"
    [2]=>
    string(5) "green"
    [3]=>
    string(4) "blue"
    [4]=>
    string(5) "black"
  }

function cube($n){
    return ($n * $n * $n);
  }
  $a = [1, 2, 3, 4, 5];
  $b = array_map('cube', $a);
  print_r($b);

$a = [1, 2, 3, 4, 5];
  $b = array_map(fn($n) => $n * $n * $n, $a);
  print_r($b);

$factor = 10;
  $calc = function($num) use($factor){
    return $num * $factor;
  };

$factor = 10;
  $calc = fn($num) => $num * $factor;

$username = $_GET['user'] ?? ‘nobody';

$this->request->data['comments']['user_id'] = $this->request->data['comments']['user_id'] ?? 'value';

$this->request->data['comments']['user_id'] ??= ‘value’;