Question

所以我试图使用以下函数来剖析我的列名

function disectColumnName($columnName){
    echo "fieldname: " .$columnName. "<br>";
    $periodLengths = array("min","hr","dy","wk");   # Array of periodLength Options
    $periodLength = $periodLengths[array_search($columnName, $periodLengths)];  # Find which periodLength is used in columnName and sa
    $periodDuration = substr($columnName, 0, strpos($columnName,$periodLength));
    echo 'periodLength: '.$periodLength . "<br>";
    echo 'periodDuration: '.$periodDuration . "<br>";
    $movingAverages = array("e","s");
    $movingAverageLoc = $movingAverages[array_search($columnName, $movingAverages)];
    echo "movingAverageLoc: " .$movingAverageLoc . "<br>";
    $startOfString = strpos($columnName,$periodLength)+strlen($periodLength);
    $stringLength = strpos($columnName,$movingAverageLoc)-(strpos($columnName,$periodLength)+strlen($periodLength));
    # strpos($columnName,$movingAverageLoc) returns blank, should return strpos when movingAverages = "S"
    echo "StartOf: ". $startOfString . "<br>";
    echo "StrLen: ". $stringLength . "<br>";
    $movingAverage = substr($columnName,$startOfString,$stringLength);
    echo 'movingAverage: '.$movingAverage;
}

disectColumnName处于循环中，通过以下列标题进行处理 -

 array(12) { [0]=> string(7) "14min3e" [1]=> string(7) "14min4e" [2]=> string(8) "14min41e" [3]=> string(7) "14min3s" [4]=> string(8) "14min41s" [5]=> string(8) "14min32s" [6]=> string(9) "14min321s" [7]=> string(9) "15min321s" [8]=> string(8) "15min41s" [9]=> string(9) "15min321e" [10]=> string(8) "15min41e" [11]=> string(8) "15min32e" }

问题是以's'结尾的列标题没有生成正确的StringLength或movingAverageLoc（它显示的是e而不是S）。但是，如果列名称以'e'结尾，则它可以完美地运行，是什么？

以下是目前正在输出的内容：

fieldname: 14min3e
periodLength: min
periodDuration: 14
movingAverageLoc: e
StartOf: 5
StrLen: 1
movingAverage: 3

fieldname: 14min4e
periodLength: min
periodDuration: 14
movingAverageLoc: e
StartOf: 5
StrLen: 1
movingAverage: 4

fieldname: 14min41e
periodLength: min
periodDuration: 14
movingAverageLoc: e
StartOf: 5
StrLen: 2
movingAverage: 41

fieldname: 14min3s
periodLength: min
periodDuration: 14
movingAverageLoc: e
StartOf: 5
StrLen: -5
movingAverage: 

fieldname: 14min41s
periodLength: min
periodDuration: 14
movingAverageLoc: e
StartOf: 5
StrLen: -5
movingAverage: 

fieldname: 14min32s
periodLength: min
periodDuration: 14
movingAverageLoc: e
StartOf: 5
StrLen: -5
movingAverage: 

fieldname: 14min321s
periodLength: min
periodDuration: 14
movingAverageLoc: e
StartOf: 5
StrLen: -5
movingAverage: 

fieldname: 15min321s
periodLength: min
periodDuration: 15
movingAverageLoc: e
StartOf: 5
StrLen: -5
movingAverage: 

fieldname: 15min41s
periodLength: min
periodDuration: 15
movingAverageLoc: e
StartOf: 5
StrLen: -5
movingAverage: 

fieldname: 15min321e
periodLength: min
periodDuration: 15
movingAverageLoc: e
StartOf: 5
StrLen: 3
movingAverage: 321

fieldname: 15min41e
periodLength: min
periodDuration: 15
movingAverageLoc: e
StartOf: 5
StrLen: 2
movingAverage: 41

fieldname: 15min32e
periodLength: min
periodDuration: 15
movingAverageLoc: e
StartOf: 5
StrLen: 2
movingAverage: 32

Answer 1

list($periodDuration, $periodLength, $movingAverage, $movingAverageLoc) =
    sscanf($columnName, '%d%[a-z]%d%[a-z]');

Answer 2

在这一行：

$movingAverageLoc = $movingAverages[array_search($columnName, $movingAverages)];

这部分：

array_search($columnName, $movingAverages)

正在搜索数组，数组（“e”，“s”）作为列名，例如“15min41e”。除非你的列名是“e”或“s”，否则它总是会返回false。因此，对于您的所有示例数据，它基本上都是这样做的：

$movingAverageLoc = $movingAverages[false];

与：

相同

$movingAverageLoc = $movingAverages[0];

这就是为什么你总是得到$ movingAverageLoc的“e”。你至少需要修理那条线。

然而，有更容易（不那么令人困惑）的方式来做你想做的事情。使用preg_split获取一个：

$string = "1wk2dy5hr15min431e";
$res = preg_split('~([0-9]+)([a-z]+)~i', $string, -1, PREG_SPLIT_DELIM_CAPTURE|PREG_SPLIT_NO_EMPTY);
print_r($res);

结果：

Array
(
    [0] => 1
    [1] => wk
    [2] => 2
    [3] => dy
    [4] => 5
    [5] => hr
    [6] => 15
    [7] => min
    [8] => 431
    [9] => e
)

strpos，strlen和substr的问题

2 个答案: