仅从数组中选择不同的值答案

【问题标题】：selecting only distinct values from an array仅从数组中选择不同的值
【发布时间】：2013-09-28 10:05:02
【问题描述】：

在这里，我有以下变量 $countries_all：

Array ( 
  [0] => stdClass Object 
      ( 
          [countries] => India,Afghanestan,Japan,South Africa
      ) 
  [1] => stdClass Object 
      ( 
          [countries] => Singapore,South Africa,India,Pakistan
      )
  [2] => stdClass Object 
      ( 
          [countries] => Japan,Australia,India
      ) 
)

但我需要创建仅包含唯一值的第二个数组 $countries：

Array ( 
  [0] => stdClass Object 
      ( 
          [countries] => India
      )
  [1] => stdClass Object 
      ( 
          [countries] => Afghanestan
      )
  [2] => stdClass Object 
      ( 
          [countries] => Japan
      )
  [3] => stdClass Object 
      ( 
          [countries] => South Africa
      )
  [4] => stdClass Object 
      ( 
          [countries] => Singapore
      )
  [5] => stdClass Object 
      ( 
          [countries] => Pakistan
      )
  [6] => stdClass Object 
      ( 
          [countries] => Japan
      )
  [7] => stdClass Object 
      ( 
          [countries] => Australia
      ) 
)

对于按 (,) 进行分割，我使用了以下方法

foreach ($countries_all as $list){
    $countrieslist=explode(',', $list->countries);
    foreach ($countrieslist as $uni_countries){
        echo $uni_countries;
    }
}

但是如何从上面的案例中获取唯一值。

谁能帮帮我

提前致谢。

EDIT1

这里我还有一个与上述问题相关的查询。

现在我得到了唯一值，

如何从数据库中获取唯一值的结果

例如，我想要所有具有（如）国家为“印度”的结果

【问题讨论】：

你从哪里得到$countries？应该是 $uni_countries 吗？
对不起，这只是 $uni_countries

标签： php mysql loops foreach

【解决方案1】：

array_unique 函数正是您所寻找的。p>

$countries = array();
foreach ($countries_all as $list){
    $countrieslist=explode(',', $list->countries);
    foreach ($countrieslist as $country){
        $countries[] = $country;
    }
}
$countries = array_unique($countries);

【讨论】：

【解决方案2】：

$newlist = array();
foreach ($countries_list as $list){
    $countrieslist=explode(',', $list->countries);
    foreach ($countrieslist as $uni_countries){
        echo $uni_countries;
        $newlist[] = $uni_countries){
    }
}
array_unique($newlist);

【讨论】：

【解决方案3】：

$commasplit = function ($list) { return explode(',', $list->countries); };
$countrieslist = array_unique(call_user_func_array('array_merge', array_map($commasplit, $countries_list)));

【讨论】：

【解决方案4】：

你可以试试这个

$countrieslist = array();
foreach ($countries_all as $list){
    $countrieslist[] = explode(',', $list->countries);
}
$array = array_unique(array_reduce($countrieslist,'array_merge', array()));

An Example.

【讨论】：

【解决方案5】：

试试这个：

$uniqueCountries = array();

foreach ($countries_list as $list){
    $countrieslist=explode(',', $list->countries);
    foreach ($countrieslist as $country){
        if (!in_array($country, $uniqueCountries)) {
            //adding to list
            $uniqueCountries[] = $country
        } else {
             echo $country, ' already in list', PHP_EOL;
        }
    }
}

$uniqueCoutries 包含所有找到的 coutries，没有重复

【讨论】：