Matrix: Add the get_num_correct_choices function #739047

question.php

@@ -462,4 +462,17 @@ public function get_num_selected_choices(array $response): int {
         }
         return $numselected;
     }
+
+    /**
+     * Returns the count of correct answers for the question.
+     *
+     * @return int the number of choices that are correct.
+     */
+    public function get_num_correct_choices(): int {
+        $numcorrect = 0;
+        foreach ($this->rows as $row) {
+            $numcorrect += count($row->correctanswers);
+        }
+        return $numcorrect;
+    }
 }

tests/question_multiple_test.php

@@ -354,4 +354,11 @@ public function test_get_num_parts_grade_partial(): void {
         // Two responsess are given and both are correct (Second and third row have not been answered).
         $this->assertEquals([2, 7], $question->get_num_parts_grade_partial(['rowanswers0_1' => '1', 'rowanswers0_3' => '1']));
     }
+
+    public function test_get_num_correct_choices(): void {
+        $question = \test_question_maker::make_question('oumatrix', 'food_multiple');
+
+        // Correct number of choices are expected.
+        $this->assertEquals(7, $question->get_num_correct_choices());
+    }
 }