Commit 6d917566 by Qiang Xue

added more methods to ArrayHelper.

parent c4d11c6a
......@@ -71,8 +71,14 @@ class ArrayHelper extends \yii\base\Component
}
/**
* Converts an array such that it is indexed by the specified column values or anonymous function results.
* This method should be used only for two or higher dimensional arrays.
* Indexes an array according to a specified key.
* The input array should be multidimensional or an array of objects.
*
* The key can be a key name of the sub-array, a property name of object, or an anonymous
* function which returns the key value given an array element.
*
* If a key value is null, the corresponding array element will be discarded and not put in the result.
*
* For example,
*
* ~~~
......@@ -84,18 +90,17 @@ class ArrayHelper extends \yii\base\Component
* // the result is:
* // array(
* // '123' => array('id' => '123', 'data' => 'abc'),
* // '345' => array('id' => '123', 'data' => 'abc'),
* // '345' => array('id' => '345', 'data' => 'def'),
* // )
*
* // using anonymous function
* $result = ArrayHelper::index($array, function(element) {
* return $element['id'];
* });
* ~~~
*
* Note that if an index value is null, it will NOT be added to the resulting array.
*
* @param array $array the multidimensional array that needs to be indexed
* @param mixed $key the column name or anonymous function whose result will be used to index the array
* @param array $array the array that needs to be indexed
* @param string|\Closure $key the column name or anonymous function whose result will be used to index the array
* @return array the indexed array (the input array will be kept intact.)
*/
public static function index($array, $key)
......@@ -110,11 +115,97 @@ class ArrayHelper extends \yii\base\Component
}
} else {
foreach ($array as $element) {
if (is_object($element)) {
if (($value = $element->$key) !== null) {
$result[$value] = $element;
}
} elseif (is_array($element)) {
if (isset($element[$key]) && $element[$key] !== null) {
$result[$element[$key]] = $element;
}
}
}
}
return $result;
}
/**
* Returns the values of a specified column in an array.
* The input array should be multidimensional or an array of objects.
*
* For example,
*
* ~~~
* $array = array(
* array('id' => '123', 'data' => 'abc'),
* array('id' => '345', 'data' => 'def'),
* );
* $result = ArrayHelper::column($array, 'id');
* // the result is: array( '123', '345')
*
* // using anonymous function
* $result = ArrayHelper::column($array, function(element) {
* return $element['id'];
* });
* ~~~
*
* @param array $array
* @param string|\Closure $key
* @return array the list of column values
*/
public static function column($array, $key)
{
$result = array();
if ($key instanceof \Closure) {
foreach ($array as $element) {
$result[] = call_user_func($key, $element);
}
} else {
foreach ($array as $element) {
if (is_object($element)) {
$result[] = $element->$key;
} elseif (is_array($element)) {
$result[] = $element[$key];
}
}
}
return $result;
}
/**
* Builds a map (key-value pairs) from a multidimensional array or an array of objects.
* The `$from` and `$to` parameters specify the key names or property names to set up the map.
*
* For example,
*
* ~~~
* $array = array(
* array('id' => '123', 'data' => 'abc'),
* array('id' => '345', 'data' => 'def'),
* );
* $result = ArrayHelper::map($array, 'id', 'data');
* // the result is:
* // array(
* // '123' => 'abc',
* // '345' => 'def',
* // )
* ~~~
*
* @param $array
* @param $from
* @param $to
* @return array
*/
public static function map($array, $from, $to)
{
$result = array();
foreach ($array as $element) {
if (is_object($element)) {
$result[$element->$from] = $element->$to;
} elseif (is_array($element)) {
$result[$element[$from]] = $element[$to];
}
}
return $result;
}
}
\ No newline at end of file
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