Question

我有一个像：

这样的数组

$arr[0] = ("1-3-2011","1","15"); //date(dd-mm-yyyy),id,amt
$arr[1] = ("1-4-2011","2","5");
$arr[2] = ("12-3-2011","6","20");
$arr[3] = ("1-3-2011","10","10");
$arr[4] = ("12-3-2011","3","10");
$arr[5] = ("1-4-2011","5","15");
$arr[6] = ("1-3-2011","7","15");

由此我需要生成像

这样的精简数组

$newarr[0] = ("1-3-2011","1,7,10","40"); 
$newarr[0] = ("1-4-2011","2,5","20");
..
...

基本上第一个是多维数组，包含日期，ID和数量。在新数组中，我需要为每个唯一日期压缩前一个，将id作为重复日期的csv字符串和添加的数量。

最有效的方法是什么，性能明智？

Answer 1

这样的事情应该这样做：

$newarr = array();

foreach($arr as $row) {
    if(!isset($newarr[$row[0]])) {
        $newarr[$row[0]] = array('ids' => array(), 'amount' => 0);
    }
    $newarr[$row[0]]['ids'][] = $row[1];
    $newarr[$row[0]]['amount'] += $row[2];
}

foreach($newarr as $key => &$row) {
    $row = array($key, implode(',', $row['ids']), $row['amount']);
} unset($row);

工作示例：

http://codepad.org/UmiDKLYJ

在PHP中生成像这样的压缩数组的最佳方法是什么？

1 个答案: