yokada · July 31, 2021 08:25 · Jul 31, 2021
diff --git a/col2idx.php b/col2idx.php
@@ -0,0 +1,16 @@
+<?php
+
+/**
+ * convert column name to index number.
+ * 
+ * @param string $col 'Z', 'AA', 'ZAA'
+ */
+function col2idx($col = 'AZ') {
+    $idx = 0;
+    $k = count(range('A', 'Z'));
+    $cols = array_reverse(str_split($cols));
+    foreach ($cols as $i => $c) {
+        $idx += count(range('A', $c)) * pow($k, $i);
+    }
+    return $idx;
+}