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Array operation class_PHP tutorial
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- 2016-07-20 11:12:421016browse
<span class</span><span ArrayHelper{
</span><span /*</span><span *
* 从数组中删除空白的元素（包括只有空白字符的元素）
*
* 用法：
* @code php
* $arr = array('', 'test', ' ');
* ArrayHelper::removeEmpty($arr);
*
* dump($arr);
* // 输出结果中将只有 'test'
* @endcode
*
* @param array $arr 要处理的数组
* @param boolean $trim 是否对数组元素调用 trim 函数
</span><span */</span>
<span static</span> <span function</span> removeEmpty(& <span $arr</span>, <span $trim</span> = <span TRUE</span><span )
{
</span><span foreach</span> (<span $arr</span> <span as</span> <span $key</span> => <span $value</span><span )
{
</span><span if</span> (<span is_array</span>(<span $value</span><span ))
{
self</span>::removeEmpty(<span $arr</span>[<span $key</span><span ]);
}
</span><span else</span><span
{
</span><span $value</span> = <span trim</span>(<span $value</span><span );
</span><span if</span> (<span $value</span> == ''<span )
{
</span><span unset</span>(<span $arr</span>[<span $key</span><span ]);
}
</span><span elseif</span> (<span $trim</span><span )
{
</span><span $arr</span>[<span $key</span>] = <span $value</span><span ;
}
}
}
}
</span><span /*</span><span *
* 从一个二维数组中返回指定键的所有值
*
* 用法：
* @code php
* $rows = array(
* array('id' => 1, 'value' => '1-1'),
* array('id' => 2, 'value' => '2-1'),
* );
* $values = ArrayHelper::getCols($rows, 'value');
*
* dump($values);
* // 输出结果为
* // array(
* // '1-1',
* // '2-1',
* // )
* @endcode
*
* @param array $arr 数据源
* @param string $col 要查询的键
*
* @return array 包含指定键所有值的数组
</span><span */</span>
<span static</span> <span function</span> getCols(<span $arr</span>, <span $col</span><span )
{
</span><span $ret</span> = <span array</span><span ();
</span><span foreach</span> (<span $arr</span> <span as</span> <span $row</span><span )
{
</span><span if</span> (<span isset</span>(<span $row</span>[<span $col</span><span ])) {
</span><span $ret</span>[] = <span $row</span>[<span $col</span><span ];
}
}
</span><span return</span> <span $ret</span><span ;
}
</span><span /*</span><span *
* 将一个二维数组转换为 HashMap，并返回结果
*
* 用法1：
* @code php
* $rows = array(
* array('id' => 1, 'value' => '1-1'),
* array('id' => 2, 'value' => '2-1'),
* );
* $hashmap = ArrayHelper::toHashmap($rows, 'id', 'value');
*
* dump($hashmap);
* // 输出结果为
* // array(
* // 1 => '1-1',
* // 2 => '2-1',
* // )
* @endcode
*
* 如果省略 $valueField 参数，则转换结果每一项为包含该项所有数据的数组。
*
* 用法2：
* @code php
* $rows = array(
* array('id' => 1, 'value' => '1-1'),
* array('id' => 2, 'value' => '2-1'),
* );
* $hashmap = ArrayHelper::toHashmap($rows, 'id');
*
* dump($hashmap);
* // 输出结果为
* // array(
* // 1 => array('id' => 1, 'value' => '1-1'),
* // 2 => array('id' => 2, 'value' => '2-1'),
* // )
* @endcode
*
* @param array $arr 数据源
* @param string $keyField 按照什么键的值进行转换
* @param string $valueField 对应的键值
*
* @return array 转换后的 HashMap 样式数组
</span><span */</span>
<span static</span> <span function</span> toHashmap(<span $arr</span>, <span $keyField</span>, <span $valueField</span> = <span NULL</span><span )
{
</span><span $ret</span> = <span array</span><span ();
</span><span if</span> (<span $valueField</span><span )
{
</span><span foreach</span> (<span $arr</span> <span as</span> <span $row</span><span )
{
</span><span $ret</span>[<span $row</span>[<span $keyField</span>]] = <span $row</span>[<span $valueField</span><span ];
}
}
</span><span else</span><span
{
</span><span foreach</span> (<span $arr</span> <span as</span> <span $row</span><span )
{
</span><span $ret</span>[<span $row</span>[<span $keyField</span>]] = <span $row</span><span ;
}
}
</span><span return</span> <span $ret</span><span ;
}
</span><span /*</span><span *
* 将一个二维数组按照指定字段的值分组
*
* 用法：
* @code php
* $rows = array(
* array('id' => 1, 'value' => '1-1', 'parent' => 1),
* array('id' => 2, 'value' => '2-1', 'parent' => 1),
* array('id' => 3, 'value' => '3-1', 'parent' => 1),
* array('id' => 4, 'value' => '4-1', 'parent' => 2),
* array('id' => 5, 'value' => '5-1', 'parent' => 2),
* array('id' => 6, 'value' => '6-1', 'parent' => 3),
* );
* $values = ArrayHelper::groupBy($rows, 'parent');
*
* dump($values);
* // 按照 parent 分组的输出结果为
* // array(
* // 1 => array(
* // array('id' => 1, 'value' => '1-1', 'parent' => 1),
* // array('id' => 2, 'value' => '2-1', 'parent' => 1),
* // array('id' => 3, 'value' => '3-1', 'parent' => 1),
* // ),
* // 2 => array(
* // array('id' => 4, 'value' => '4-1', 'parent' => 2),
* // array('id' => 5, 'value' => '5-1', 'parent' => 2),
* // ),
* // 3 => array(
* // array('id' => 6, 'value' => '6-1', 'parent' => 3),
* // ),
* // )
* @endcode
*
* @param array $arr 数据源
* @param string $keyField 作为分组依据的键名
*
* @return array 分组后的结果
</span><span */</span>
<span static</span> <span function</span> groupBy(<span $arr</span>, <span $keyField</span><span )
{
</span><span $ret</span> = <span array</span><span ();
</span><span foreach</span> (<span $arr</span> <span as</span> <span $row</span><span )
{
</span><span $key</span> = <span $row</span>[<span $keyField</span><span ];
</span><span $ret</span>[<span $key</span>][] = <span $row</span><span ;
}
</span><span return</span> <span $ret</span><span ;
}
</span><span /*</span><span *
* 将一个平面的二维数组按照指定的字段转换为树状结构
*
* 用法：
* @code php
* $rows = array(
* array('id' => 1, 'value' => '1-1', 'parent' => 0),
* array('id' => 2, 'value' => '2-1', 'parent' => 0),
* array('id' => 3, 'value' => '3-1', 'parent' => 0),
*
* array('id' => 7, 'value' => '2-1-1', 'parent' => 2),
* array('id' => 8, 'value' => '2-1-2', 'parent' => 2),
* array('id' => 9, 'value' => '3-1-1', 'parent' => 3),
* array('id' => 10, 'value' => '3-1-1-1', 'parent' => 9),
* );
*
* $tree = ArrayHelper::tree($rows, 'id', 'parent', 'nodes');
*
* dump($tree);
* // 输出结果为：
* // array(
* // array('id' => 1, ..., 'nodes' => array()),
* // array('id' => 2, ..., 'nodes' => array(
* // array(..., 'parent' => 2, 'nodes' => array()),
* // array(..., 'parent' => 2, 'nodes' => array()),
* // ),
* // array('id' => 3, ..., 'nodes' => array(
* // array('id' => 9, ..., 'parent' => 3, 'nodes' => array(
* // array(..., , 'parent' => 9, 'nodes' => array(),
* // ),
* // ),
* // )
* @endcode
*
* 如果要获得任意节点为根的子树，可以使用 $refs 参数：
* @code php
* $refs = null;
* $tree = ArrayHelper::tree($rows, 'id', 'parent', 'nodes', $refs);
*
* // 输出 id 为 3 的节点及其所有子节点
* $id = 3;
* dump($refs[$id]);
* @endcode
*
* @param array $arr 数据源
* @param string $keyNodeId 节点ID字段名
* @param string $keyParentId 节点父ID字段名
* @param string $keyChildrens 保存子节点的字段名
* @param boolean $refs 是否在返回结果中包含节点引用
*
* return array 树形结构的数组
</span><span */</span>
<span static</span> <span function</span> toTree(<span $arr</span>, <span $keyNodeId</span>, <span $keyParentId</span> = 'parent_id', <span $keyChildrens</span> = 'childrens', & <span $refs</span> = <span NULL</span><span )
{
</span><span $refs</span> = <span array</span><span ();
</span><span foreach</span> (<span $arr</span> <span as</span> <span $offset</span> => <span $row</span><span )
{
</span><span $arr</span>[<span $offset</span>][<span $keyChildrens</span>] = <span array</span><span ();
</span><span $refs</span>[<span $row</span>[<span $keyNodeId</span>]] =& <span $arr</span>[<span $offset</span><span ];
}
</span><span $tree</span> = <span array</span><span ();
</span><span foreach</span> (<span $arr</span> <span as</span> <span $offset</span> => <span $row</span><span )
{
</span><span $parentId</span> = <span $row</span>[<span $keyParentId</span><span ];
</span><span if</span> (<span $parentId</span><span )
{
</span><span if</span> (!<span isset</span>(<span $refs</span>[<span $parentId</span><span ]))
{
</span><span $tree</span>[] =& <span $arr</span>[<span $offset</span><span ];
</span><span continue</span><span ;
}
</span><span $parent</span> =& <span $refs</span>[<span $parentId</span><span ];
</span><span $parent</span>[<span $keyChildrens</span>][] =& <span $arr</span>[<span $offset</span><span ];
}
</span><span else</span><span
{
</span><span $tree</span>[] =& <span $arr</span>[<span $offset</span><span ];
}
}
</span><span return</span> <span $tree</span><span ;
}
</span><span /*</span><span *
* 将树形数组展开为平面的数组
*
* 这个方法是 tree() 方法的逆向操作。
*
* @param array $tree 树形数组
* @param string $keyChildrens 包含子节点的键名
*
* @return array 展开后的数组
</span><span */</span>
<span static</span> <span function</span> treeToArray(<span $tree</span>, <span $keyChildrens</span> = 'childrens'<span )
{
</span><span $ret</span> = <span array</span><span ();
</span><span if</span> (<span isset</span>(<span $tree</span>[<span $keyChildrens</span>]) && <span is_array</span>(<span $tree</span>[<span $keyChildrens</span><span ]))
{
</span><span foreach</span> (<span $tree</span>[<span $keyChildrens</span>] <span as</span> <span $child</span><span )
{
</span><span $ret</span> = <span array_merge</span>(<span $ret</span>, self::treeToArray(<span $child</span>, <span $keyChildrens</span><span ));
}
</span><span unset</span>(<span $node</span>[<span $keyChildrens</span><span ]);
</span><span $ret</span>[] = <span $tree</span><span ;
}
</span><span else</span><span
{
</span><span $ret</span>[] = <span $tree</span><span ;
}
</span><span return</span> <span $ret</span><span ;
}
</span><span /*</span><span *
* 根据指定的键对数组排序
*
* 用法：
* @code php
* $rows = array(
* array('id' => 1, 'value' => '1-1', 'parent' => 1),
* array('id' => 2, 'value' => '2-1', 'parent' => 1),
* array('id' => 3, 'value' => '3-1', 'parent' => 1),
* array('id' => 4, 'value' => '4-1', 'parent' => 2),
* array('id' => 5, 'value' => '5-1', 'parent' => 2),
* array('id' => 6, 'value' => '6-1', 'parent' => 3),
* );
*
* $rows = ArrayHelper::sortByCol($rows, 'id', SORT_DESC);
* dump($rows);
* // 输出结果为：
* // array(
* // array('id' => 6, 'value' => '6-1', 'parent' => 3),
* // array('id' => 5, 'value' => '5-1', 'parent' => 2),
* // array('id' => 4, 'value' => '4-1', 'parent' => 2),
* // array('id' => 3, 'value' => '3-1', 'parent' => 1),
* // array('id' => 2, 'value' => '2-1', 'parent' => 1),
* // array('id' => 1, 'value' => '1-1', 'parent' => 1),
* // )
* @endcode
*
* @param array $array 要排序的数组
* @param string $keyname 排序的键
* @param int $dir 排序方向
*
* @return array 排序后的数组
</span><span */</span>
<span static</span> <span function</span> sortByCol(<span $array</span>, <span $keyname</span>, <span $dir</span> =<span SORT_ASC)
{
</span><span return</span> self::sortByMultiCols(<span $array</span>, <span array</span>(<span $keyname</span> => <span $dir</span><span ));
}
</span><span /*</span><span *
* 将一个二维数组按照多个列进行排序，类似 SQL 语句中的 ORDER BY
*
* 用法：
* @code php
* $rows = ArrayHelper::sortByMultiCols($rows, array(
* 'parent' => SORT_ASC,
* 'name' => SORT_DESC,
* ));
* @endcode
*
* @param array $rowset 要排序的数组
* @param array $args 排序的键
*
* @return array 排序后的数组
</span><span */</span>
<span static</span> <span function</span> sortByMultiCols(<span $rowset</span>, <span $args</span><span )
{
</span><span $sortArray</span> = <span array</span><span ();
</span><span $sortRule</span> = ''<span ;
</span><span foreach</span> (<span $args</span> <span as</span> <span $sortField</span> => <span $sortDir</span><span )
{
</span><span foreach</span> (<span $rowset</span> <span as</span> <span $offset</span> => <span $row</span><span )
{
</span><span $sortArray</span>[<span $sortField</span>][<span $offset</span>] = <span $row</span>[<span $sortField</span><span ];
}
</span><span $sortRule</span> .= '$sortArray[\'' . <span $sortField</span> . '\'], ' . <span $sortDir</span> . ', '<span ;
}
</span><span if</span> (<span empty</span>(<span $sortArray</span>) || <span empty</span>(<span $sortRule</span><span )) {
</span><span return</span> <span $rowset</span><span ;
}
</span><span eval</span>('array_multisort(' . <span $sortRule</span> . '$rowset);'<span );
</span><span return</span> <span $rowset</span><span ;
}
}</span>
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