Brush up the qmlsurfacegallery example

- Use modern string literals
- Use member initialization
- Streamline the code a bit with algorithms

Task-number: QTBUG-110700
Change-Id: Iad834c22f4dc14858b0f5da4fc2a550de9906072
Reviewed-by: Tomi Korpipää <tomi.korpipaa@qt.io>
(cherry picked from commit acdaea0c859ba7b78756011ea60ec2765b5a8f04)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

1 files changed, 3 insertions, 3 deletions

diff --git a/examples/datavisualization/qmlsurfacegallery/datasource.h b/examples/datavisualization/qmlsurfacegallery/datasource.h
index 5cfebbd8..bac5eeb2 100644
--- a/examples/datavisualization/qmlsurfacegallery/datasource.h
+++ b/examples/datavisualization/qmlsurfacegallery/datasource.h
@@ -16,7 +16,7 @@ class DataSource : public QObject
     QML_ELEMENT
     //! [2]
 public:
-    explicit DataSource(QObject *parent = 0);
+    explicit DataSource(QObject *parent = nullptr);
     virtual ~DataSource();
 
     //! [1]
@@ -31,8 +31,8 @@ private:
     void clearData();
 
     QList<QSurfaceDataArray> m_data;
-    int m_index;
-    QSurfaceDataArray *m_resetArray;
+    int m_index = -1;
+    QSurfaceDataArray *m_resetArray = nullptr;
 };
 
 #endif