diff --git a/src/bitboard.cpp b/src/bitboard.cpp
index 371bb12a..a491fc77 100644
--- a/src/bitboard.cpp
+++ b/src/bitboard.cpp
@@ -36,10 +36,10 @@ Bitboard StarSquareBB12;
 const std::string Bitboards::pretty(Bitboard b)
 {
     std::string str = "+---+---+---+---+---+---+---+---+\n";
-    for (File file = FILE_A; file <= FILE_C; ++file) {
-        for (Rank rank = RANK_1; rank <= RANK_8; ++rank) {
+    for (File f = FILE_A; f <= FILE_C; ++f) {
+        for (Rank r = RANK_1; r <= RANK_8; ++r) {
 
-            str += b & make_square(file, rank) ? "| X " : "|   ";
+            str += b & make_square(f, r) ? "| X " : "|   ";
         }
 
         str += "|\n+---+---+---+---+---+---+---+---+\n";
diff --git a/src/misc.h b/src/misc.h
index dad5f10c..7b021b4f 100644
--- a/src/misc.h
+++ b/src/misc.h
@@ -36,7 +36,7 @@ void start_logger(const std::string &fname);
 void* std_aligned_alloc(size_t alignment, size_t size);
 void std_aligned_free(void* ptr);
 #ifdef ALIGNED_LARGE_PAGES
-void* aligned_large_pages_alloc(size_t size); // memory aligned by page size, min alignment: 4096 bytes
+void* aligned_large_pages_alloc(size_t allocSize); // memory aligned by page size, min alignment: 4096 bytes
 void aligned_large_pages_free(void* mem); // nop if mem == nullptr
 #endif // ALIGNED_LARGE_PAGES
 
@@ -116,7 +116,7 @@ class PRNG
     }
 
 public:
-    PRNG(uint64_t seed) : s(seed)
+    explicit PRNG(uint64_t seed) : s(seed)
     {
         assert(seed);
     }
diff --git a/src/movepick.cpp b/src/movepick.cpp
index 801849b4..ccca2b2d 100644
--- a/src/movepick.cpp
+++ b/src/movepick.cpp
@@ -55,12 +55,12 @@ void MovePicker::score()
     Square from, to;
     Move m;
 
-    int ourMillsCount = 0;
-    int theirMillsCount = 0;
-    int ourPieceCount = 0;
-    int theirPiecesCount = 0;
-    int bannedCount = 0;
-    int emptyCount = 0;
+    int ourMillsCount;
+    int theirMillsCount;
+    int ourPieceCount;
+    int theirPiecesCount;
+    int bannedCount;
+    int emptyCount;
 
     while (cur++->move != MOVE_NONE) {
         m = cur->move;
diff --git a/src/movepick.h b/src/movepick.h
index 48f78403..035fd201 100644
--- a/src/movepick.h
+++ b/src/movepick.h
@@ -44,7 +44,7 @@ class MovePicker
 public:
     MovePicker(const MovePicker &) = delete;
     MovePicker &operator=(const MovePicker &) = delete;
-    MovePicker(Position &position);
+    explicit MovePicker(Position &p);
 
     Move next_move();
 
@@ -68,7 +68,7 @@ public:
 
     int moveCount { 0 };
 
-    int move_count()
+    int move_count() const
     {
         return moveCount;
     }
diff --git a/src/option.h b/src/option.h
index 68e86a77..9e4a03b0 100644
--- a/src/option.h
+++ b/src/option.h
@@ -29,7 +29,7 @@ public:
         isAutoRestart = enabled;
     }
 
-    bool getAutoRestart()
+    bool getAutoRestart() const
     {
         return isAutoRestart;
     }
@@ -39,7 +39,7 @@ public:
         isAutoChangeFirstMove = enabled;
     }
 
-    bool getAutoChangeFirstMove()
+    bool getAutoChangeFirstMove() const
     {
         return isAutoChangeFirstMove;
     }
@@ -49,7 +49,7 @@ public:
         resignIfMostLose = enabled;
     }
 
-    bool getResignIfMostLose()
+    bool getResignIfMostLose() const
     {
         return resignIfMostLose;
     }
@@ -60,7 +60,7 @@ public:
     // variation between different games against an opponent that tries to do the
     // same sequence of moves. By default, shuffling is enabled.
 
-    bool getShufflingEnabled()
+    bool getShufflingEnabled() const
     {
         return shufflingEnabled;
     }
@@ -79,7 +79,7 @@ public:
 #endif
     }
 
-    bool isEndgameLearningEnabled()
+    bool isEndgameLearningEnabled() const
     {
 #ifdef ENDGAME_LEARNING_FORCE
         return  true;
@@ -93,7 +93,7 @@ public:
         IDSEnabled = enabled;
     }
 
-    bool getIDSEnabled()
+    bool getIDSEnabled() const
     {
         return IDSEnabled;
     }
@@ -105,7 +105,7 @@ public:
         depthExtension = enabled;
     }
 
-    bool getDepthExtension()
+    bool getDepthExtension() const
     {
         return depthExtension;
     }
@@ -117,7 +117,7 @@ public:
         openingBook = enabled;
     }
 
-    bool getOpeningBook()
+    bool getOpeningBook() const
     {
         return openingBook;
     }
diff --git a/src/position.h b/src/position.h
index d6d871fa..619f28d5 100644
--- a/src/position.h
+++ b/src/position.h
@@ -135,10 +135,10 @@ public:
 
     static void print_board();
 
-    int piece_on_board_count(Color c);
-    int piece_in_hand_count(Color c);
+    int piece_on_board_count(Color c) const;
+    int piece_in_hand_count(Color c) const;
 
-    int piece_to_remove_count();
+    int piece_to_remove_count() const;
 
     static bool is_star_square(Square s);
 
@@ -146,13 +146,13 @@ public:
 
     // Other helpers
     bool select_piece(Square s);
-    bool select_piece(File file, Rank rank);
+    bool select_piece(File f, Rank r);
 
     void put_piece(Piece pc, Square s);
-    bool put_piece(File file, Rank rank);
+    bool put_piece(File f, Rank r);
     bool put_piece(Square s, bool updategameRecords = false);
 
-    bool remove_piece(File file, Rank rank);
+    bool remove_piece(File f, Rank r);
     bool remove_piece(Square s, bool updategameRecords = false);
 
     bool move_piece(File f1, Rank r1, File f2, Rank r2);
@@ -169,7 +169,7 @@ public:
     int pieceToRemoveCount{ 0 };
     int gamePly { 0 };
     Color sideToMove { NOCOLOR };
-    Thread *thisThread;
+    Thread *thisThread {nullptr};
     StateInfo st;
 
     /// Mill Game
@@ -342,7 +342,7 @@ inline bool Position::move_piece(Square from, Square to)
 
 inline Piece *Position::get_board()
 {
-    return (Piece *)board;
+    return static_cast<Piece *>(board);
 }
 
 inline Square Position::current_square() const
@@ -365,17 +365,17 @@ inline const char *Position::get_record() const
     return record;
 }
 
-inline int Position::piece_on_board_count(Color c)
+inline int Position::piece_on_board_count(Color c) const
 {
     return pieceOnBoardCount[c];
 }
 
-inline int Position::piece_in_hand_count(Color c)
+inline int Position::piece_in_hand_count(Color c) const
 {
     return pieceInHandCount[c];
 }
 
-inline int Position::piece_to_remove_count()
+inline int Position::piece_to_remove_count() const
 {
     return pieceToRemoveCount;
 }
diff --git a/src/rule.cpp b/src/rule.cpp
index 1cf78218..779f509b 100644
--- a/src/rule.cpp
+++ b/src/rule.cpp
@@ -129,7 +129,7 @@ const struct Rule RULES[N_RULES] = {
 
 bool set_rule(int ruleIdx)
 {
-    if (ruleIdx <= 0 || ruleIdx > N_RULES) {
+    if (ruleIdx <= 0 || ruleIdx >= N_RULES) {
         return false;
     }
 
diff --git a/src/stack.h b/src/stack.h
index 7fc1da3b..575c2b6a 100644
--- a/src/stack.h
+++ b/src/stack.h
@@ -105,7 +105,7 @@ public:
         return p + 1;
     }
 
-    inline size_t length()
+    inline size_t length() const
     {
         return (sizeof(T) * size());
     }
diff --git a/src/stopwatch.h b/src/stopwatch.h
index d5361e6f..8f627608 100644
--- a/src/stopwatch.h
+++ b/src/stopwatch.h
@@ -60,8 +60,8 @@ struct timer {
   using time_point = typename Clock::time_point;
   using duration = typename Clock::duration;
 
-  timer(const duration duration) noexcept : expiry(Clock::now() + duration) {}
-  timer(const time_point expiry) noexcept : expiry(expiry) {}
+  explicit timer(const duration duration) noexcept : expiry(Clock::now() + duration) {}
+  explicit timer(const time_point expiry) noexcept : expiry(expiry) {}
 
   bool done(time_point now = Clock::now()) const noexcept {
     return now >= expiry;
diff --git a/src/test/test.h b/src/test/test.h
index 978c720d..b8a253ec 100644
--- a/src/test/test.h
+++ b/src/test/test.h
@@ -37,7 +37,7 @@ class Test : public QDialog
     Q_OBJECT
 
 public:
-    explicit Test(QWidget *parent = nullptr, QString key = "Key0");
+    explicit Test(QWidget *parent = nullptr, QString k = "Key0");
     ~Test();
 
     void setKey(QString k)
diff --git a/src/thread.h b/src/thread.h
index 7d667302..61e1160e 100644
--- a/src/thread.h
+++ b/src/thread.h
@@ -77,7 +77,7 @@ public:
     string nextMove();
     Depth adjustDepth();
 
-    int getTimeLimit()
+    int getTimeLimit() const
     {
         return timeLimit;
     }
diff --git a/src/tt.h b/src/tt.h
index 868db7c6..3b91e365 100644
--- a/src/tt.h
+++ b/src/tt.h
@@ -53,14 +53,14 @@ struct TTEntry
 private:
     friend class TranspositionTable;
 
-    int8_t  value8;
-    int8_t  depth8;
-    uint8_t genBound8;
+    int8_t  value8 {0};
+    int8_t  depth8 {0};
+    uint8_t genBound8 {0};
 #ifdef TRANSPOSITION_TABLE_FAKE_CLEAN
-    uint8_t age8;
+    uint8_t age8 {0};
 #endif // TRANSPOSITION_TABLE_FAKE_CLEAN
 #ifdef TT_MOVE_ENABLE
-    Move ttMove;
+    Move ttMove {MOVE_NONE};
 #endif // TT_MOVE_ENABLE
 };
 
diff --git a/src/ui/qt/game.cpp b/src/ui/qt/game.cpp
index ff1dcf4a..6e170ff9 100644
--- a/src/ui/qt/game.cpp
+++ b/src/ui/qt/game.cpp
@@ -231,12 +231,11 @@ void Game::gameReset()
     // 2：先手第2子； 3：后手第2子
     // ......
     PieceItem::Models md;
-    PieceItem *newP;
 
     for (int i = 0; i < rule.piecesCount; i++) {
         // 先手的棋子
         md = isInverted ? PieceItem::Models::whitePiece : PieceItem::Models::blackPiece;
-        newP = new PieceItem;
+        PieceItem *newP = new PieceItem;
         newP->setModel(md);
         newP->setPos(scene.pos_p1);
         newP->setNum(i + 1);
@@ -360,7 +359,7 @@ void Game::setRule(int ruleNo, int stepLimited /*= -1*/, int timeLimited /*= -1*
     elapsedSeconds[BLACK] = elapsedSeconds[WHITE] = 0;
 
     char record[64] = { 0 };
-    if (sprintf(record, "r%1u s%03u t%02u", r + 1, rule.maxStepsLedToDraw, 0) <= 0) {
+    if (sprintf(record, "r%1d s%03d t%02d", r + 1, rule.maxStepsLedToDraw, 0) <= 0) {
         assert(0);
     }
     string cmd(record);
@@ -519,6 +518,7 @@ void Game::playSound(GameSound soundType, Color c)
         break;
     };
 
+#ifndef DONOT_PLAY_SOUND
     QString soundPath = QString::fromStdString(soundDir + filename);
 
 #ifndef TRAINING_MODE
@@ -526,7 +526,6 @@ void Game::playSound(GameSound soundType, Color c)
         return;
     }
 
-#ifndef DONOT_PLAY_SOUND
     if (hasSound) {
         QSound::play(soundPath);
     }
@@ -781,14 +780,14 @@ bool Game::isAIsTurn()
 }
 
 // 关键槽函数，根据QGraphicsScene的信号和状态来执行选子、落子或去子
-bool Game::actionPiece(QPointF pos)
+bool Game::actionPiece(QPointF p)
 {
 #ifndef TRAINING_MODE
     // 点击非落子点，不执行
-    File file;
-    Rank rank;
+    File f;
+    Rank r;
 
-    if (!scene.pos2polar(pos, file, rank)) {
+    if (!scene.pos2polar(p, f, r)) {
         return false;
     }
 
@@ -848,11 +847,11 @@ bool Game::actionPiece(QPointF pos)
     // 判断执行选子、落子或去子
     bool result = false;
     PieceItem *piece = nullptr;
-    QGraphicsItem *item = scene.itemAt(pos, QTransform());
+    QGraphicsItem *item = scene.itemAt(p, QTransform());
 
     switch (position.get_action()) {
     case Action::place:
-        if (position.put_piece(file, rank)) { 
+        if (position.put_piece(f, r)) { 
             if (position.get_action() == Action::remove) {
                 // 播放成三音效
                 playSound(GameSound::mill, position.side_to_move());
@@ -871,7 +870,7 @@ bool Game::actionPiece(QPointF pos)
         piece = qgraphicsitem_cast<PieceItem *>(item);
         if (!piece)
             break;
-        if (position.select_piece(file, rank)) {
+        if (position.select_piece(f, r)) {
             // 播放选子音效
             playSound(GameSound::select, position.side_to_move());
             result = true;
@@ -882,7 +881,7 @@ bool Game::actionPiece(QPointF pos)
         break;
 
     case Action::remove:
-        if (position.remove_piece(file, rank)) {
+        if (position.remove_piece(f, r)) {
             // 播放音效
             playSound(GameSound::remove, position.side_to_move());
             result = true;
@@ -1344,7 +1343,7 @@ bool Game::updateScence(Position &p)
     int ipos = p.current_square();
     if (ipos) {
         key = board[p.current_square()];
-        ipos = key & B_STONE ? (key - B_STONE_1) * 2 : (key - W_STONE_1) * 2 + 1;
+        ipos = (key & B_STONE) ? (key - B_STONE_1) * 2 : (key - W_STONE_1) * 2 + 1;
         if (ipos >= 0 && ipos < nTotalPieces) {
             currentPiece = pieceList.at(static_cast<size_t>(ipos));
             currentPiece->setSelected(true);
@@ -1588,7 +1587,7 @@ void Game::setTips()
             reasonStr = turnStr + "超时判负。";
             break;
         case GameOverReason::drawReasonThreefoldRepetition:
-            tips = "三次重复局面判和。";
+            reasonStr = "三次重复局面判和。";
             break;
         default:
             break;
diff --git a/src/ui/qt/game.h b/src/ui/qt/game.h
index ae9ce477..4fbd21b3 100644
--- a/src/ui/qt/game.h
+++ b/src/ui/qt/game.h
@@ -80,7 +80,7 @@ class Game : public QObject
     Q_OBJECT
 
 public:
-    Game(
+    explicit Game(
 #ifndef TRAINING_MODE
         GameScene &scene,
 #endif
@@ -356,7 +356,7 @@ public slots:
 
     // 更新棋局显示，每步后执行才能刷新局面
     bool updateScence();
-    bool updateScence(Position &position);
+    bool updateScence(Position &p);
 
 #ifdef NET_FIGHT_SUPPORT
     // 显示网络配置窗口
diff --git a/src/ui/qt/gamewindow.cpp b/src/ui/qt/gamewindow.cpp
index b36cd94c..a2441c70 100644
--- a/src/ui/qt/gamewindow.cpp
+++ b/src/ui/qt/gamewindow.cpp
@@ -1098,26 +1098,26 @@ void MillGameWindow::on_actionAbout_A_triggered()
 }
 
 #ifdef MOBILE_APP_UI
-void MillGameWindow::mousePressEvent(QMouseEvent *event)
+void MillGameWindow::mousePressEvent(QMouseEvent *mouseEvent)
 {
-    if (event->button() == Qt::LeftButton) {
+    if (mouseEvent->button() == Qt::LeftButton) {
         m_move = true;
-        m_startPoint = event->globalPos();
+        m_startPoint = mouseEvent->globalPos();
         m_windowPoint = this->frameGeometry().topLeft();
     }
 }
 
-void MillGameWindow::mouseMoveEvent(QMouseEvent *event)
+void MillGameWindow::mouseMoveEvent(QMouseEvent *mouseEvent)
 {
-    if (event->buttons() & Qt::LeftButton) {
-        QPoint relativePos = event->globalPos() - m_startPoint;
+    if (mouseEvent->buttons() & Qt::LeftButton) {
+        QPoint relativePos = mouseEvent->globalPos() - m_startPoint;
         this->move(m_windowPoint + relativePos );
     }
 }
 
-void MillGameWindow::mouseReleaseEvent(QMouseEvent *event)
+void MillGameWindow::mouseReleaseEvent(QMouseEvent *mouseEvent)
 {
-    if (event->button() == Qt::LeftButton) {
+    if (mouseEvent->button() == Qt::LeftButton) {
         m_move = false;
     }
 }
diff --git a/src/ui/qt/gamewindow.h b/src/ui/qt/gamewindow.h
index 95e94bd3..6c271a5f 100644
--- a/src/ui/qt/gamewindow.h
+++ b/src/ui/qt/gamewindow.h
@@ -51,9 +51,9 @@ protected:
     bool eventFilter(QObject *watched, QEvent *event) override;
     void closeEvent(QCloseEvent *event) override;
 #ifdef MOBILE_APP_UI
-    void mousePressEvent(QMouseEvent *event) override;
-    void mouseMoveEvent(QMouseEvent *event) override;
-    void mouseReleaseEvent(QMouseEvent *event) override;
+    void mousePressEvent(QMouseEvent *mouseEvent) override;
+    void mouseMoveEvent(QMouseEvent *mouseEvent) override;
+    void mouseReleaseEvent(QMouseEvent *mouseEvent) override;
 #endif /* MOBILE_APP_UI */
 
 private slots:
diff --git a/src/ui/qt/pieceitem.cpp b/src/ui/qt/pieceitem.cpp
index b2d65f90..46f329c8 100644
--- a/src/ui/qt/pieceitem.cpp
+++ b/src/ui/qt/pieceitem.cpp
@@ -168,21 +168,21 @@ void PieceItem::paint(QPainter *painter,
     }
 }
 
-void PieceItem::mousePressEvent(QGraphicsSceneMouseEvent *event)
+void PieceItem::mousePressEvent(QGraphicsSceneMouseEvent *mouseEvent)
 {
     // 鼠标按下时变为握住的手形
     setCursor(Qt::ClosedHandCursor);
-    QGraphicsItem::mousePressEvent(event);
+    QGraphicsItem::mousePressEvent(mouseEvent);
 }
 
-void PieceItem::mouseMoveEvent(QGraphicsSceneMouseEvent *event)
+void PieceItem::mouseMoveEvent(QGraphicsSceneMouseEvent *mouseEvent)
 {
-    QGraphicsItem::mouseMoveEvent(event);
+    QGraphicsItem::mouseMoveEvent(mouseEvent);
 }
 
-void PieceItem::mouseReleaseEvent(QGraphicsSceneMouseEvent *event)
+void PieceItem::mouseReleaseEvent(QGraphicsSceneMouseEvent *mouseEvent)
 {
     // 鼠标松开时变为伸开的手形
     setCursor(Qt::OpenHandCursor);
-    QGraphicsItem::mouseReleaseEvent(event);
+    QGraphicsItem::mouseReleaseEvent(mouseEvent);
 }
diff --git a/src/ui/qt/pieceitem.h b/src/ui/qt/pieceitem.h
index 650c2fc3..8d5f48e5 100644
--- a/src/ui/qt/pieceitem.h
+++ b/src/ui/qt/pieceitem.h
@@ -114,10 +114,10 @@ private:
     enum Models model;
 
     // 棋子序号，黑白都从1开始
-    int num = 1;
+    int num  {1};
 
     // 棋子尺寸
-    int size;
+    int size {0};
 
     // 有无删除线
     bool deleted {false};
@@ -126,10 +126,10 @@ private:
     bool showNum {false};
 
     // 选中子标识线宽度
-    int selectLineWeight;
+    int selectLineWeight {0};
 
     // 删除线宽度
-    int removeLineWeight;
+    int removeLineWeight {0};
 
     // 选中线颜色
     QColor selectLineColor;
diff --git a/src/ui/qt/server.h b/src/ui/qt/server.h
index 2d6a71b6..fdd45c0a 100644
--- a/src/ui/qt/server.h
+++ b/src/ui/qt/server.h
@@ -42,7 +42,7 @@ class Server : public QDialog
 public:
     explicit Server(QWidget *parent = nullptr, uint16_t port = 33333);
     ~Server();
-    void setAction(const QString &action);
+    void setAction(const QString &a);
     void setPort(uint16_t p)
     {
         port = p;