Question

如何确定两个数组中是否存在给定对象？我的目的是找到添加的对象，删除的对象和更改的对象。

class Foo
{
    private $id, $backup;
    public $p1, $p2, $p3;
    public function __construct($id, $p1, $p2, $p3){
        $this->id=$id;
        $this->p1=$p1;
        $this->p2=$p2;
        $this->p3=$p3;
        $this->backup=[$p1, $p2, $p3];
    }
}

$collection1=[
    Foo(1,'a','aa','aaa'),
    Foo(2,'b','bb','bbb'),
    Foo(5,'c','cc','ccc'),
    Foo(9,'d','dd','ddd'),
];
$collection2=$arr1;

$collection1[]=Foo(9,'d','dd','ddd');
unset($collection1[2]);
$collection1[0]->p2='bla'; //Will modify both $collection1 and $collection2

Answer 1

来自：https://secure.php.net/manual/en/language.oop5.object-comparison.php

使用identity运算符（===）时，对象变量是相同的当且仅当他们引用同一个类的同一个实例时。

<?php
class Foo
{
    public $bar;
    public function __construct($bar)
    {
        $this->bar = $bar;
    }
}

$one = [new Foo(1),new Foo(2),new Foo(3)];
$two = $one;

var_dump($one[0] === $two[1]);
var_dump($one[0] === $two[0]);

输出：

bool(false) bool(true)

比较一组对象

1 个答案: