Question

Сreate一个大数组，然后它排序，然后我应该得到例如排序数组的前n个元素。

创建数组：

foreach ($array_RESPONSEdata as $key => $row) {
 $new_created_time[$key] = $row['DATE_PIC'];
 $new_thumbnail[$key] = $row['LINK_PIC'];
 $new_tags_name [$key] = $row['TAG_PIC'];
}

在get数组的输出处，如下所示：

Array (
[0] => Array ( [DATE_PIC] => 1376566005 [LINK_PIC] => http://distilleryimage3.s3.amazonaws.com/90ebfcc2059d11e381c522000a9e035f_5.jpg [TAG_PIC] => test )
[1] => Array ( [DATE_PIC] => 1376222415 [LINK_PIC] => http://distilleryimage9.s3.amazonaws.com/957a78a4027d11e3a72522000a1fb586_5.jpg [TAG_PIC] => test )
[2] => Array ( [DATE_PIC] => 1374685904 [LINK_PIC] => http://distilleryimage2.s3.amazonaws.com/1dbe356ef48411e2931722000a1fc67c_5.jpg [TAG_PIC] => test )
[3] => Array ( [DATE_PIC] => 1373909177 [LINK_PIC] => http://distilleryimage0.s3.amazonaws.com/0fd9b22adce711e2a7ab22000a1f97eb_5.jpg [TAG_PIC] => test )
[4] => Array ( [DATE_PIC] => 1372089573 [LINK_PIC] => http://distilleryimage0.s3.amazonaws.com/0fd9b22adce711e2a7ab22000a1f97eb_5.jpg [TAG_PIC] => test )
[5] => Array ( [DATE_PIC] => 1371468982 [LINK_PIC] => http://distilleryimage0.s3.amazonaws.com/0fd9b22adce711e2a7ab22000a1f97eb_5.jpg [TAG_PIC] => test )
)

接下来，按密钥DATE_PIC：

对数组进行排序

array_multisort($new_created_time, SORT_DESC, $array_RESPONSEdata);

获取一个反向排序的数组。

问题：现在如何排序后，前三行输出？

Answer 1

您实际上不需要将数组分开，如果它适合您的应用程序，这将节省一些内存：

<?php

    // Will sort using 'DATE_PIC' as index.
    array_multisort( $array_RESPONSEdata, SORT_ASC );

    // We'll define a buffer, so PHP doesn't need to echo every time (list-style).
    $buffer = array();

    /**
     * You mentioned 'get the first n elements', to specify how many
     * rows you want to get, you can specify the max count in a for loop
     * array_multisort reassigns numeric index keys in order after sorting.
     *
     * e.g. If we want 5 records to count:
     * $max = 5;
     *
     * If you want all that is returned you can do this:
     * $max = count( $array_RESPONSEdata );
     */
    $max = 5;

    for( $n = 0; $n < $max; $n++ )
    {
        $buffer[] = '<ul>';
        $buffer[] = '<li>' . $array_RESPONSEdata[$n]['TAG_PIC'] . '</li>';
        $buffer[] = '<li>' . $array_RESPONSEdata[$n]['DATE_PIC'] . '</li>';
        $buffer[] = '<li><img src="' . $array_RESPONSEdata[$n]['LINK_PIC'] . '" alt="' . $array_RESPONSEdata[$n]['TAG_PIC'] . '"/>';
        $buffer[] = '</ul>';
    }

    // And now the output magic (Not really):
    echo implode( "\r\n", $buffer );
?>

当然，根据需要构建HTML，这仅仅是例如。顺便说一句，作为参考，我使用"\r\n"将我的缓冲区拼接在一起，因为源打印在不同的行上，这样可以很容易地看到源代码中的html / css调整情况。

我可以使用条件创建输出数组

1 个答案: