array_diff() 过滤两个对象数组时返回空结果

Question

var_dump($this->externalProjects);
var_dump($this->projects);
$result = array_diff($this->externalProjects, $this->projects);
print_r($result);

输出：

array (size=6) // external projects
  0 => 
    object(CloseCall\ValueObject\Project)[79]
      private 'name' => string '(A11) Tyre Pyrolysis Plant, Civil, Mech & Elec' (length=46)
  1 => 
    object(CloseCall\ValueObject\Project)[80]
      private 'name' => string '(B) - Millerhill New Depot Proposal' (length=35)
  2 => 
    object(CloseCall\ValueObject\Project)[81]
      private 'name' => string '(B13) Port of Tyne Wood Pellet Handling Facilities' (length=50)
  3 => 
    object(CloseCall\ValueObject\Project)[82]
      private 'name' => string '(C) - Millerhill Proposed New Depot' (length=35)
  4 => 
    object(CloseCall\ValueObject\Project)[83]
      private 'name' => string '(S) - EGIP New Depot Proposal' (length=29)
  5 => 
    object(CloseCall\ValueObject\Project)[85]
      private 'name' => string '00352 Allerton - Building fabric & structure survey' (length=51)

array (size=1) //projects
  0 => 
    object(CloseCall\ValueObject\Project)[15]
      private 'name' => string '(A11) Tyre Pyrolysis Plant, Civil, Mech & Elec' (length=46)

// no output for array_diff

Answer 1

array_diff()

不适合过滤多维数据。 您的数组包含对象，因此调用

array_udiff()

并在回调中对整个对象进行 3 路比较（因为访问私有名称属性将涉及更多卷积）。 演示

namespace CloseCall\ValueObject;

class Project {
    public function __construct(private string $name) {}
}

// Populate externalProjects and projects arrays
$externalProjects = [
    new Project('(A11) Tyre Pyrolysis Plant, Civil, Mech & Elec'),
    new Project('(B) - Millerhill New Depot Proposal'),
    new Project('(B13) Port of Tyne Wood Pellet Handling Facilities'),
    new Project('(C) - Millerhill Proposed New Depot'),
    new Project('(S) - EGIP New Depot Proposal'),
    new Project('00352 Allerton - Building fabric & structure survey')
];

$projects = [
    new Project('(A11) Tyre Pyrolysis Plant, Civil, Mech & Elec')
];

var_dump(
    array_udiff(
        $externalProjects,
        $projects,
        fn($a, $b) => $a <=> $b
    )
);

输出：

array(5) {
  [1]=>
  object(CloseCall\ValueObject\Project)#2 (1) {
    ["name":"CloseCall\ValueObject\Project":private]=>
    string(35) "(B) - Millerhill New Depot Proposal"
  }
  [2]=>
  object(CloseCall\ValueObject\Project)#3 (1) {
    ["name":"CloseCall\ValueObject\Project":private]=>
    string(50) "(B13) Port of Tyne Wood Pellet Handling Facilities"
  }
  [3]=>
  object(CloseCall\ValueObject\Project)#4 (1) {
    ["name":"CloseCall\ValueObject\Project":private]=>
    string(35) "(C) - Millerhill Proposed New Depot"
  }
  [4]=>
  object(CloseCall\ValueObject\Project)#5 (1) {
    ["name":"CloseCall\ValueObject\Project":private]=>
    string(29) "(S) - EGIP New Depot Proposal"
  }
  [5]=>
  object(CloseCall\ValueObject\Project)#6 (1) {
    ["name":"CloseCall\ValueObject\Project":private]=>
    string(51) "00352 Allerton - Building fabric & structure survey"
  }
}