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More perforan version of stringFromColumnIndex that takes advantage of the PHP 5.3 modified ternary

This commit is contained in:
MarkBaker 2017-09-10 22:51:05 +01:00
parent d576855031
commit 77b3c12fbc
1 changed files with 13 additions and 20 deletions
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33
src/PhpSpreadsheet/Cell.php
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@ -856,32 +856,25 @@ class Cell
/**
* String from columnindex.
*
* @param int $pColumnIndex Column index (A = 0)
* @param int $columnIndex Column index (A = 0)
*
* @return string
*/
public static function stringFromColumnIndex($pColumnIndex)
public static function stringFromColumnIndex($columnIndex)
{
// Using a lookup cache adds a slight memory overhead, but boosts speed
// caching using a static within the method is faster than a class static,
// though it's additional memory overhead
static $_indexCache = [];
static $indexCache = array();
if (!isset($_indexCache[$pColumnIndex])) {
// Determine column string
if ($pColumnIndex < 26) {
$_indexCache[$pColumnIndex] = chr(65 + $pColumnIndex);
} elseif ($pColumnIndex < 702) {
$_indexCache[$pColumnIndex] = chr(64 + ($pColumnIndex / 26)) .
chr(65 + $pColumnIndex % 26);
} else {
$_indexCache[$pColumnIndex] = chr(64 + (($pColumnIndex - 26) / 676)) .
chr(65 + ((($pColumnIndex - 26) % 676) / 26)) .
chr(65 + $pColumnIndex % 26);
if (!isset($indexCache[$columnIndex])) {
$indexValue = $columnIndex + 1;
$base26 = null;
do {
$characterValue = ($indexValue % 26) ?: 26;
$indexValue = ($indexValue - $characterValue) / 26;
$base26 = chr($characterValue + 64).($base26 ?: '');
} while ($indexValue > 0);
$indexCache[$columnIndex] = $base26;
}
}
return $_indexCache[$pColumnIndex];
return $indexCache[$columnIndex];
}
/**