diff --git a/src/ccmain/pagesegmain.cpp b/src/ccmain/pagesegmain.cpp
index 5ebcb3f70a..acd6a5aaa5 100644
--- a/src/ccmain/pagesegmain.cpp
+++ b/src/ccmain/pagesegmain.cpp
@@ -108,8 +108,10 @@ int Tesseract::SegmentPage(const char *input_file, BLOCK_LIST *blocks, Tesseract
   // If a UNLV zone file can be found, use that instead of segmentation.
   if (!PSM_COL_FIND_ENABLED(pageseg_mode) && input_file != nullptr && input_file[0] != '\0') {
     std::string name = input_file;
-    std::size_t lastdot = name.find_last_of(".");
-    name = name.substr(0, lastdot);
+    auto lastdot = name.find_last_of('.');
+    if (lastdot != std::string::npos) {
+      name.resize(lastdot);
+    }
     read_unlv_file(name, width, height, blocks);
   }
   if (blocks->empty()) {
diff --git a/src/ccutil/ambigs.cpp b/src/ccutil/ambigs.cpp
index 34d68968f8..5aafedb187 100644
--- a/src/ccutil/ambigs.cpp
+++ b/src/ccutil/ambigs.cpp
@@ -39,12 +39,9 @@ static const char kIllegalUnicharMsg[] = "Illegal unichar %s in ambiguity specif
 //   UNICHAR_LEN * (MAX_AMBIG_SIZE + 1) for each part of the ambig
 const int kMaxAmbigStringSize = UNICHAR_LEN * (MAX_AMBIG_SIZE + 1);
 
-AmbigSpec::AmbigSpec() {
+AmbigSpec::AmbigSpec() : correct_ngram_id(INVALID_UNICHAR_ID), type(NOT_AMBIG), wrong_ngram_size(0) {
   wrong_ngram[0] = INVALID_UNICHAR_ID;
   correct_fragments[0] = INVALID_UNICHAR_ID;
-  correct_ngram_id = INVALID_UNICHAR_ID;
-  type = NOT_AMBIG;
-  wrong_ngram_size = 0;
 }
 
 // Initializes the ambigs by adding a nullptr pointer to each table.
diff --git a/src/ccutil/unicharset.cpp b/src/ccutil/unicharset.cpp
index c0aea1f3e6..b29ec3b7fe 100644
--- a/src/ccutil/unicharset.cpp
+++ b/src/ccutil/unicharset.cpp
@@ -824,7 +824,7 @@ bool UNICHARSET::load_via_fgets(
     stream >> std::setw(255) >> unichar >> std::hex >> properties >> std::dec;
     // stream.flags(std::ios::dec);
     if (stream.fail()) {
-      fprintf(stderr, "%s:%u failed\n", __FILE__, __LINE__);
+      fprintf(stderr, "%s:%d failed\n", __FILE__, __LINE__);
       return false;
     }
     auto position = stream.tellg();
diff --git a/src/classify/adaptive.cpp b/src/classify/adaptive.cpp
index 3139cce9be..1b7bf5fb0a 100644
--- a/src/classify/adaptive.cpp
+++ b/src/classify/adaptive.cpp
@@ -59,13 +59,12 @@ PERM_CONFIG_STRUCT::~PERM_CONFIG_STRUCT() {
   delete[] Ambigs;
 }
 
-ADAPT_CLASS_STRUCT::ADAPT_CLASS_STRUCT() {
-  NumPermConfigs = 0;
-  MaxNumTimesSeen = 0;
-  TempProtos = NIL_LIST;
-
-  PermProtos = NewBitVector(MAX_NUM_PROTOS);
-  PermConfigs = NewBitVector(MAX_NUM_CONFIGS);
+ADAPT_CLASS_STRUCT::ADAPT_CLASS_STRUCT() :
+  NumPermConfigs(0),
+  MaxNumTimesSeen(0),
+  PermProtos(NewBitVector(MAX_NUM_PROTOS)),
+  PermConfigs(NewBitVector(MAX_NUM_CONFIGS)),
+  TempProtos(NIL_LIST) {
   zero_all_bits(PermProtos, WordsInVectorOfSize(MAX_NUM_PROTOS));
   zero_all_bits(PermConfigs, WordsInVectorOfSize(MAX_NUM_CONFIGS));
 
@@ -124,16 +123,13 @@ int Classify::GetFontinfoId(ADAPT_CLASS_STRUCT *Class, uint8_t ConfigId) {
 ///
 /// @param MaxProtoId  max id of any proto in new config
 /// @param FontinfoId font information from pre-trained templates
-TEMP_CONFIG_STRUCT::TEMP_CONFIG_STRUCT(int maxProtoId, int fontinfoId) {
-  int NumProtos = maxProtoId + 1;
-
-  Protos = NewBitVector(NumProtos);
-
-  NumTimesSeen = 1;
-  MaxProtoId = maxProtoId;
-  ProtoVectorSize = WordsInVectorOfSize(NumProtos);
+TEMP_CONFIG_STRUCT::TEMP_CONFIG_STRUCT(int maxProtoId, int fontinfoId) :
+  NumTimesSeen(1),
+  ProtoVectorSize(WordsInVectorOfSize(maxProtoId + 1)),
+  MaxProtoId(maxProtoId),
+  Protos(NewBitVector(maxProtoId + 1)),
+  FontinfoId(fontinfoId) {
   zero_all_bits(Protos, ProtoVectorSize);
-  FontinfoId = fontinfoId;
 }
 
 TEMP_CONFIG_STRUCT::~TEMP_CONFIG_STRUCT() {
diff --git a/src/classify/clusttool.cpp b/src/classify/clusttool.cpp
index 543378d6b3..de8b1f5cb8 100644
--- a/src/classify/clusttool.cpp
+++ b/src/classify/clusttool.cpp
@@ -277,7 +277,7 @@ void WritePrototype(FILE *File, uint16_t N, PROTOTYPE *Proto) {
     fprintf(File, "insignificant ");
   }
   WriteProtoStyle(File, static_cast<PROTOSTYLE>(Proto->Style));
-  fprintf(File, "%6d\n\t", Proto->NumSamples);
+  fprintf(File, "%6u\n\t", Proto->NumSamples);
   WriteNFloats(File, N, &Proto->Mean[0]);
   fprintf(File, "\t");
 
diff --git a/src/tesseract.cpp b/src/tesseract.cpp
index 1ed7fcf398..ac42d2ec35 100644
--- a/src/tesseract.cpp
+++ b/src/tesseract.cpp
@@ -78,8 +78,8 @@ static void Win32WarningHandler(const char *module, const char *fmt, va_list ap)
 
 class AutoWin32ConsoleOutputCP {
 public:
-  explicit AutoWin32ConsoleOutputCP(UINT codeCP) {
-    oldCP_ = GetConsoleOutputCP();
+  explicit AutoWin32ConsoleOutputCP(UINT codeCP) :
+    oldCP_(GetConsoleOutputCP()) {
     SetConsoleOutputCP(codeCP);
   }
   ~AutoWin32ConsoleOutputCP() {
diff --git a/src/textord/devanagari_processing.cpp b/src/textord/devanagari_processing.cpp
index bad6edb50f..13da1374c0 100644
--- a/src/textord/devanagari_processing.cpp
+++ b/src/textord/devanagari_processing.cpp
@@ -38,15 +38,16 @@ INT_VAR(devanagari_split_debuglevel, 0, "Debug level for split shiro-rekha proce
 BOOL_VAR(devanagari_split_debugimage, 0,
          "Whether to create a debug image for split shiro-rekha process.");
 
-ShiroRekhaSplitter::ShiroRekhaSplitter() {
-  orig_pix_ = nullptr;
-  segmentation_block_list_ = nullptr;
-  splitted_image_ = nullptr;
-  global_xheight_ = kUnspecifiedXheight;
-  perform_close_ = false;
-  debug_image_ = nullptr;
-  pageseg_split_strategy_ = NO_SPLIT;
-  ocr_split_strategy_ = NO_SPLIT;
+ShiroRekhaSplitter::ShiroRekhaSplitter() :
+  orig_pix_(nullptr),
+  splitted_image_(nullptr),
+  pageseg_split_strategy_(NO_SPLIT),
+  ocr_split_strategy_(NO_SPLIT),
+  debug_image_(nullptr),
+  segmentation_block_list_(nullptr),
+  global_xheight_(kUnspecifiedXheight),
+  perform_close_(false)
+{
 }
 
 ShiroRekhaSplitter::~ShiroRekhaSplitter() {
diff --git a/src/textord/tabfind.cpp b/src/textord/tabfind.cpp
index f6ba2b8477..fb6d99ae04 100644
--- a/src/textord/tabfind.cpp
+++ b/src/textord/tabfind.cpp
@@ -67,8 +67,8 @@ TabFind::TabFind(int gridsize, const ICOORD &bleft, const ICOORD &tright, TabVec
     : AlignedBlob(gridsize, bleft, tright)
     , resolution_(resolution)
     , image_origin_(0, tright.y() - 1)
-    , v_it_(&vectors_) {
-  width_cb_ = nullptr;
+    , v_it_(&vectors_)
+    , width_cb_(nullptr) {
   v_it_.add_list_after(vlines);
   SetVerticalSkewAndParallelize(vertical_x, vertical_y);
   using namespace std::placeholders; // for _1
diff --git a/src/training/pango/pango_font_info.cpp b/src/training/pango/pango_font_info.cpp
index 5adbb26f9e..aefe73417e 100644
--- a/src/training/pango/pango_font_info.cpp
+++ b/src/training/pango/pango_font_info.cpp
@@ -521,9 +521,9 @@ bool FontUtils::IsAvailableFont(const char *input_query_desc, std::string *best_
     *best_match = selected_desc_str;
     // Clip the ending ' 0' if there is one. It seems that, if there is no
     // point size on the end of the fontname, then Pango always appends ' 0'.
-    int len = best_match->size();
+    auto len = best_match->size();
     if (len > 2 && best_match->at(len - 1) == '0' && best_match->at(len - 2) == ' ') {
-      *best_match = best_match->substr(0, len - 2);
+      best_match->resize(len - 2);
     }
   }
   g_free(selected_desc_str);
diff --git a/src/viewer/scrollview.cpp b/src/viewer/scrollview.cpp
index f5336c589a..73bd3c5fc2 100644
--- a/src/viewer/scrollview.cpp
+++ b/src/viewer/scrollview.cpp
@@ -307,7 +307,7 @@ void ScrollView::Initialize(const char *name, int x_pos, int y_pos, int x_size,
   // Set up an actual Window on the client side.
   char message[kMaxMsgSize];
   snprintf(message, sizeof(message),
-           "w%u = luajava.newInstance('com.google.scrollview.ui"
+           "w%d = luajava.newInstance('com.google.scrollview.ui"
            ".SVWindow','%s',%u,%u,%u,%u,%u,%u,%u)\n",
            window_id_, window_name_, window_id_, x_pos, y_pos, x_size, y_size, x_canvas_size,
            y_canvas_size);
@@ -393,7 +393,7 @@ void ScrollView::SendMsg(const char *format, ...) {
   va_end(args);
 
   char form[kMaxMsgSize];
-  snprintf(form, sizeof(form), "w%u:%s\n", window_id_, message);
+  snprintf(form, sizeof(form), "w%d:%s\n", window_id_, message);
 
   stream_->Send(form);
 }
@@ -532,7 +532,7 @@ void ScrollView::AlwaysOnTop(bool b) {
 // Adds a message entry to the message box.
 void ScrollView::AddMessage(const char *message) {
   char form[kMaxMsgSize];
-  snprintf(form, sizeof(form), "w%u:%s", window_id_, message);
+  snprintf(form, sizeof(form), "w%d:%s", window_id_, message);
 
   char *esc = AddEscapeChars(form);
   SendMsg("addMessage(\"%s\")", esc);
diff --git a/src/wordrec/wordrec.cpp b/src/wordrec/wordrec.cpp
index ceaad04431..be6590688a 100644
--- a/src/wordrec/wordrec.cpp
+++ b/src/wordrec/wordrec.cpp
@@ -99,10 +99,10 @@ Wordrec::Wordrec()
                   "Save alternative paths found during chopping"
                   " and segmentation search",
                   params())
-    , pass2_ok_split(0.0f) {
-  prev_word_best_choice_ = nullptr;
-  language_model_ = std::make_unique<LanguageModel>(&get_fontinfo_table(), &(getDict()));
-  fill_lattice_ = nullptr;
+    , language_model_(std::make_unique<LanguageModel>(&get_fontinfo_table(), &(getDict())))
+    , pass2_ok_split(0.0f)
+    , prev_word_best_choice_(nullptr)
+    , fill_lattice_(nullptr) {
 }
 
 } // namespace tesseract
diff --git a/unittest/mastertrainer_test.cc b/unittest/mastertrainer_test.cc
index b6dcc5bb5a..30f4bf4e04 100644
--- a/unittest/mastertrainer_test.cc
+++ b/unittest/mastertrainer_test.cc
@@ -156,9 +156,9 @@ class MasterTrainerTest : public testing::Test {
     return file::JoinPath(FLAGS_test_tmpdir, name);
   }
 
-  MasterTrainerTest() {
-    shape_table_ = nullptr;
-    master_trainer_ = nullptr;
+  MasterTrainerTest() :
+    shape_table_(nullptr),
+    master_trainer_(nullptr) {
   }
   ~MasterTrainerTest() override {
     delete shape_table_;