13

如果我有这样的数组:

array [
       y => 35
       x => 51
       z => 35
       c_3 => 4
       c_1 => 54
       c_6 => 53
       c_9 => 52
] 

我想得到数组:

array [c_3=>4, c_1=>54, c_6=>53, c_9=>52]

如何过滤掉没有以 开头的键的元素c_

4

7 回答 7

10

尝试这个 :

$filtred = array();

foreach($yourArray as $key => $value)
  if(preg_match('/c_\d/',$key))
    $filtred[] = $value;

print_r($filtred);
于 2012-08-13T11:28:46.590 回答
7

尝试这个

 //your array
    $arr1 = array (
           "y" => 35,
           "x" => 51,
           "z" => 35,
           "c_3" => 4,
           "c_1" => 54,
           "c_6" => 53,
           "c_9" => 52
    );
// Array with keys you want
    $arr2 =  array (
           "c_3" => '',
           "c_1" => '',
           "c_6" => '',
           "c_9" => ''
    );
//use array_intersect_key to find the common  ;)
    print_r(array_intersect_key($arr1,$arr2));
于 2012-08-13T11:59:05.123 回答
6

检查此解决方案array_filter()

 $arr = [
   'y' => 35,
   'x' => 51,
   'z' => 35,
   'c_3' => 4,
   'c_1' => 54,
   'c_6' => 53,
   'c_9' => 52,
 ];

 $filtered = array_filter($arr, function($v) use($arr){
   return preg_match('#c_\d#', array_search($v, $arr));
 });

以下解决方案适用于 PHP >= 5.6.0

 $filtered = array_filter($arr, function($k){
   return preg_match('#c_\d#', $k);
 }, ARRAY_FILTER_USE_KEY);

这两种解决方案都有效,我已经检查过了。

于 2015-08-13T13:31:25.313 回答
2

您可以尝试使用array_filter().

php 文档页面上有一些有趣的示例。其中之一涵盖过滤数组键。

于 2012-08-13T11:29:57.710 回答
0

如果您只想选择已知键,请使用 array_slice:http ://php.net/manual/en/function.array-slice.php。在这里,您有按键过滤数组的解决方案:PHP:如何使用 array_filter() 过滤数组键?

于 2012-08-13T11:28:13.953 回答
0

我已经尝试过上述解决方案,但上述解决方案均不适用于我PHP 5.6

所以,我尝试并使用了对我有用的不同解决方案......

$subArray = array();

foreach($arryDetails as $key => $value)
  if(preg_match('/^c_/',$key))
    $subArray[$key] = $value;

print_r($subArray);
于 2019-02-27T07:01:24.120 回答
0

我实际上有类似的问题并在这里寻找答案,但没有什么真正符合我的期望。

我想要一些更可重用的东西,可以在我的所有项目中使用,所以我最终编写了这个函数:

   /**
* Create a new a array containing only the key with a certain $pattern or $subString.
*
* Note: You cannot use both $subString and $pattern at once ($substring has precedence on $pattern).
*
* @param $errorMessage String to return the error message.
* @param $source Array in which we must extract data.
* @param $subString String/Int/Array substring (or array of substring) to seek in the key name.
* @param $pattern String regex for validating the key.
* @param $useValueAsKey Boolean if true it will use the value as the key in the new array (scalar values only).
*/
public static function extractSubArray(&$errorMessage, array &$source, $subString ="", $pattern = "", $useValueAsKey=false){
    
    $newArray = array();
    
    $errorMessage = "";
    
    $dbManager = GeneralDbManager::getInstance();
    
    if (empty($source)){
        
        $errorMessage = $dbManager->getErrorMessage("SOURCE_ARRAY_IS_EMPTY_ERR", "The array supplied is empty.");
    }
    elseif(empty($subString) and empty($pattern)){
        
        $errorMessage = $dbManager->getErrorMessage("NO_SUBSTR_OR_PATTERN_ERR", "There are no substring or pattern to match the keys in the array.");
    }
    elseif (!empty($subString) and !(is_string($subString) or is_numeric($subString) or is_array($subString))){
        
        $errorMessage = $dbManager->getErrorMessage("INVALID_MATCH_SUBSTRING_ERR", "The substring you supplied to match the keys is invalid.");
    }
    elseif(!empty($pattern) and !RegularExpression::testRegex($pattern)){
        
        $errorMessage = $dbManager->getErrorMessage("INVALID_MATCH_PATTERN_ERR", "The regular expression you supplied to match the keys is invalid.");
    }
    else{

        foreach ($source as $key => $value){
            
            if (self::isKeyMatchSubstring($key, $subString, $pattern)){
                
                if ($useValueAsKey and (is_string($value) or is_numeric($value))){
                    
                    $newArray[$value] = $value;     
                }
                else{
                    
                    $newArray[$key] = $value;
                }
            }       
        }
        
        if (empty($newArray)){
            
            $errorMessage = $dbManager->getErrorMessage("INVALID_MATCH_PATTERN_ERR", "We were not able to match any keys in the array with the substring or the regular expression.");
        }
    }
    
    unset($dbManager);
    
    return $newArray;
}

/**
* Validate that the $key contains the $substring (string or array) or match the $pattern.
*
* @param $key String to validate
* @param $subString String/Int/Array containing the subString to seek.
* @param $pattern String regex for validating the key.
*/
private static function isKeyMatchSubstring($key, $subString, $pattern){
    
    $matched = false;
    
    if (!empty($subString)){
        
        if (is_string($subString) or is_numeric($subString)){
            
            if(strpos(strtolower($key), strtolower($subString)) !== false){
                
                $matched = true;    
            }
        }
        else{ //array
            
            foreach($subString as $testString){
                
                $matched = self::isKeyMatchSubstring($key, $testString, "");
                    
                if ($matched){
                        
                    break;  
                }
            }
        }   
    }
    elseif(!empty($pattern)){
        
        $matched = preg_match($pattern, $key);
    }
    
    return $matched;
}

它使用一个名为testRegex()的函数,所以我想我也可以提供该代码:

/**
* Make sure that a regular expression works in PHP.
*
* @param $regex String the regular expression to validate.
*
* @return Boolean
*/
public static function testRegex($regex){
    
    $isValid = false;
    
    if (!empty($regex) and is_string($regex)){
        
        if (@preg_match($regex, null) !== false){
            $isValid = true;
        }
    }
    
    return $isValid;
}

而且,当然,没有单元测试的功能会有多好?

    public function testExtractSubArray(){
    
    $errorMessage = "";
    
    $source = array();
    
    //no data
    $this->assertEmpty(Tool::extractSubArray($errorMessage, $source, "", "", false));
    
    $this->assertNotEmpty($errorMessage);
    
    //no substring or pattern
    $source = array(1 => 1);
    
    
    $this->assertEmpty(Tool::extractSubArray($errorMessage, $source, "", "", false));
    
    $this->assertNotEmpty($errorMessage);
    
    
    //invalid substring
    $dbmanager = GeneralDbManager::getInstance();
    
    $this->assertEmpty(Tool::extractSubArray($errorMessage, $source, $dbmanager, "", false));
    
    $this->assertNotEmpty($errorMessage);
    
    unset($dbmanager);
    
    
    //invalid pattern
    $this->assertEmpty(Tool::extractSubArray($errorMessage, $source, "", "[]123", false));
    
    $this->assertNotEmpty($errorMessage);
    
    
    //no match
    $this->assertEmpty(Tool::extractSubArray($errorMessage, $source, "pokemon", "", false));
    
    $this->assertNotEmpty($errorMessage);
    
    
    //valid substring
    $source = array("woot1" => "homer", "woot2" => "bart", "woot3" => "lisa", "doh1" => "marge", "doh2" => "simpson");
    
    $newArray = Tool::extractSubArray($errorMessage, $source, "WOOT", "", false);
    
    
    $this->assertNotEmpty($newArray);
    
    $this->assertEmpty($errorMessage);
    
    $this->assertContains("homer", $newArray);
    
    $this->assertContains("bart", $newArray);
    
    $this->assertContains("lisa", $newArray);
    
    $this->assertNotContains("marge", $newArray);
    
    $this->assertNotContains("simpson", $newArray);
    
    
    //use value as key
    $newArray = Tool::extractSubArray($errorMessage, $source, "WOOT", "", true);
    
    
    $this->assertTrue(array_key_exists("homer", $newArray));
    
    $this->assertTrue(array_key_exists("bart", $newArray));
    
    $this->assertTrue(array_key_exists("lisa", $newArray));
    
    
    //substring array
    $source = array("stan_march" => "normal", "kyle_brofloski" => "jew", "eric_cartman" => "asshole", "kenny_mccormick" => "dead", "butters_stotch" => "pushover");
    
    $newArray = Tool::extractSubArray($errorMessage, $source, array("stan", "kyle", "cartman"), "", false);
    
    
    $this->assertNotEmpty($newArray);
    
    $this->assertEmpty($errorMessage);
    
    $this->assertContains("normal", $newArray);
    
    $this->assertContains("jew", $newArray);
    
    $this->assertContains("asshole", $newArray);
    
    $this->assertNotContains("dead", $newArray);
    
    $this->assertNotContains("pushover", $newArray);
    
    
    //regex
    $source = array("jonathan@woot.ca" => 1, "jonathan" => 2, "12345" => 3, "more $$$" => 4, "$?%$?%$%?" => 5);
    
    $newArray = Tool::extractSubArray($errorMessage, $source, "", RegularExpression::ALPHA_NUMERIC, false);
    
    
    $this->assertNotEmpty($newArray);
    
    $this->assertEmpty($errorMessage);
    
    $this->assertNotContains(1, $newArray);
    
    $this->assertContains(2, $newArray);
    
    $this->assertContains(3, $newArray);
    
    $this->assertNotContains(4, $newArray);
    
    $this->assertNotContains(5, $newArray);
}

附加说明:此代码使用getErrorMessage()方法来获取数据库中错误消息的翻译。由于这些错误消息用于调试目的,因此可以直接在代码中硬编码以提高性能(无需实例化类来获取错误消息并打开与数据库的连接)。

于 2015-08-12T19:35:54.213 回答