在特定键的基础上查找对象数组中的重复项 [英] Find duplicates in array of objects on the basis of specific keys

问题描述

我的目标是在对象数组中找到重复的对象，而不是像下面这样使用两个foreach循环正在寻找一种更好（更优雅）的方法来找到重复项：

  foreach（$ data as $ date）{
 foreach（$ data as $ innerDate）{
 if（$ date-> birthday == $ innerDate-> birthday&& 
 $ date-> street == $ innerDate- >街&& 
 $ date-> streetnr == $ innerDate-> streetnr&& 
 $ date-> zipcode == $ innerDate-> zipcode&&& ; 
 $ date-> twinid == $ innerDate-> twinid&& 
 $ date！== $ innerDate）{
 // Duple 
} 
} 
} 
  

谢谢！

---

现在，我使用以下代码，基于Tarilo的想法：

  usort（$ data，function（$ obj _a，$ obj_b）{
 if（$ obj_a-> birthday == $ obj_b-> birthday&&& 
 $ obj_a-> street == $ obj_b-> street&& 
 $ obj_a-> streetnr == $ obj_b-> streetnr&& 
 $ obj_a-> zipcode == $ obj_b-> zipcode&& 
 $ obj_a-> twinid == $ obj_b-> twinid）{
 // Duple 
} 
}）; 
  

看起来好于两个foreach-Loops; - ）

解决方案

您可以先对数组排序，然后循环排序数组。这样你只需要将当前对象与下一个/上一个对象进行比较。您当前的算法是O（n ^ 2）有效，但是在排序之后它将是（排序+循环）=（O（log n）+ O（n）））。其中n是数组中的对象数。

my goal is to find duplicates in an array of objects, but only for specific object-variables.

Instead of using two foreach-loops like the following, I am searching for a better (more elegant) way to find the duplicates:

foreach ($data as $date) {
      foreach ($data as $innerDate) {
          if ($date->birthday == $innerDate->birthday &&
              $date->street == $innerDate->street &&
              $date->streetnr == $innerDate->streetnr &&
              $date->zipcode == $innerDate->zipcode &&
              $date->twinid == $innerDate->twinid &&
              $date !== $innerDate) {
              // Duple
        }
    }
}

Thanks!

---

Now, I'm using following code, based on Tarilo's idea:

usort($data, function($obj_a, $obj_b){
      if ($obj_a->birthday == $obj_b->birthday &&
          $obj_a->street == $obj_b->street &&
          $obj_a->streetnr == $obj_b->streetnr &&
          $obj_a->zipcode == $obj_b->zipcode &&
          $obj_a->twinid == $obj_b->twinid) {
          // Duple
      }
});

Looks much better than two foreach-Loops ;-)

解决方案

You could sort the array first and then loop over the sorted array. This way you only have to compare the current object with the next/previous object. Your current algorithm is O(n^2) efficient but after sorting it would be (sorting + looping) = (O(log n) + O(n)) efficient. Where n is the number of objects in your array.

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