Exact match in VLOOKUP now returns first match

It was inconsistent with spreadsheet software before.

Closes #809

CHANGELOG.md

@@ -17,6 +17,7 @@ and this project adheres to [Semantic Versioning](https://semver.org).
 - Improve XLSX parsing speed if no readFilter is applied - [#772](https://github.com/PHPOffice/PhpSpreadsheet/issues/772)
 - Fix column names if read filter calls in XLSX reader skip columns - [#777](https://github.com/PHPOffice/PhpSpreadsheet/pull/777)
 - Fix LOOKUP function which was breaking on edge cases - [#796](https://github.com/PHPOffice/PhpSpreadsheet/issues/796)
+- Fix VLOOKUP with exact matches
 
 ## [1.5.2] - 2018-11-25
 

src/PhpSpreadsheet/Calculation/LookupRef.php

@@ -709,6 +709,7 @@ class LookupRef
 
         $rowNumber = $rowValue = false;
         foreach ($lookup_array as $rowKey => $rowData) {
+            // break if we have passed possible keys
             if ((is_numeric($lookup_value) && is_numeric($rowData[$firstColumn]) && ($rowData[$firstColumn] > $lookup_value)) ||
                 (!is_numeric($lookup_value) && !is_numeric($rowData[$firstColumn]) && (strtolower($rowData[$firstColumn]) > strtolower($lookup_value)))) {
                 break;
@@ -716,17 +717,25 @@ class LookupRef
             // remember the last key, but only if datatypes match
             if ((is_numeric($lookup_value) && is_numeric($rowData[$firstColumn])) ||
                 (!is_numeric($lookup_value) && !is_numeric($rowData[$firstColumn]))) {
+                if ($not_exact_match) {
+                    $rowNumber = $rowKey;
+                    $rowValue = $rowData[$firstColumn];
+
+                    continue;
+                } elseif ((strtolower($rowData[$firstColumn]) == strtolower($lookup_value))
+                    // Spreadsheets software returns first exact match,
+                    // we have sorted and we might have broken key orders
+                    // we want the first one (by its initial index)
+                    && (($rowNumber == false) || ($rowKey < $rowNumber))
+                ) {
                     $rowNumber = $rowKey;
                     $rowValue = $rowData[$firstColumn];
                 }
             }
+        }
 
         if ($rowNumber !== false) {
-            if ((!$not_exact_match) && ($rowValue != $lookup_value)) {
-                //    if an exact match is required, we have what we need to return an appropriate response
-                return Functions::NA();
-            }
-            //    otherwise return the appropriate value
+            // return the appropriate value
             return $lookup_array[$rowNumber][$returnColumn];
         }
 
@@ -764,29 +773,35 @@ class LookupRef
         if ((!is_array($lookup_array[$firstRow])) || ($index_number > count($lookup_array))) {
             return Functions::REF();
         }
-        $columnKeys = array_keys($lookup_array[$firstRow]);
+
         $firstkey = $f[0] - 1;
         $returnColumn = $firstkey + $index_number;
         $firstColumn = array_shift($f);
-
-        if (!$not_exact_match) {
-            $firstRowH = asort($lookup_array[$firstColumn]);
-        }
-        $rowNumber = $rowValue = false;
+        $rowNumber = null;
         foreach ($lookup_array[$firstColumn] as $rowKey => $rowData) {
-            if ((is_numeric($lookup_value) && is_numeric($rowData) && ($rowData > $lookup_value)) ||
-                (!is_numeric($lookup_value) && !is_numeric($rowData) && (strtolower($rowData) > strtolower($lookup_value)))) {
+            // break if we have passed possible keys
+            $bothNumeric = is_numeric($lookup_value) && is_numeric($rowData);
+            $bothNotNumeric = !is_numeric($lookup_value) && !is_numeric($rowData);
+            if (($bothNumeric && $rowData > $lookup_value) ||
+                ($bothNotNumeric && strtolower($rowData) > strtolower($lookup_value))) {
                 break;
             }
+
+            // Remember the last key, but only if datatypes match (as in VLOOKUP)
+            if ($bothNumeric || $bothNotNumeric) {
+                if ($not_exact_match) {
                     $rowNumber = $rowKey;
-            $rowValue = $rowData;
+
+                    continue;
+                } elseif (strtolower($rowData) === strtolower($lookup_value)
+                    && ($rowNumber === null || $rowKey < $rowNumber)
+                ) {
+                    $rowNumber = $rowKey;
+                }
+            }
         }
 
-        if ($rowNumber !== false) {
-            if ((!$not_exact_match) && ($rowValue != $lookup_value)) {
-                //  if an exact match is required, we have what we need to return an appropriate response
-                return Functions::NA();
-            }
+        if ($rowNumber !== null) {
             //  otherwise return the appropriate value
             return $lookup_array[$returnColumn][$rowNumber];
         }

tests/data/Calculation/LookupRef/HLOOKUP.php

@@ -275,4 +275,14 @@ return [
         2,
         true,
     ],
+    [
+        5,
+        'x',
+        [
+            ['Selection column', '0', '0', '0', '0', 'x', 'x', 'x', 'x', 'x'],
+            ['Value to retrieve', 1, 2, 3, 4, 5, 6, 7, 8, 9]
+        ],
+        2,
+        false
+    ]
 ];

tests/data/Calculation/LookupRef/VLOOKUP.php

@@ -291,4 +291,25 @@ return [
         2,
         true,
     ],
+    [
+        5,
+        'x',
+        [
+            [
+                'Selection column',
+                'Value to retrieve',
+            ],
+            ['0', 1],
+            ['0', 2],
+            ['0', 3],
+            ['0', 4],
+            ['x', 5],
+            ['x', 6],
+            ['x', 7],
+            ['x', 8],
+            ['x', 9],
+        ],
+        2,
+        false
+    ]
 ];