diff --git a/dom/base/nsContentUtils.cpp b/dom/base/nsContentUtils.cpp
index f91542069534..d6bcba949147 100644
--- a/dom/base/nsContentUtils.cpp
+++ b/dom/base/nsContentUtils.cpp
@@ -1105,9 +1105,8 @@ nsContentUtils::ParseHTMLInteger(const nsAString& aValue,
       if (!value.isValid()) {
         result |= eParseHTMLInteger_Error | eParseHTMLInteger_ErrorOverflow;
         break;
-      } else {
-        foundValue = true;
       }
+      foundValue = true;
     } else if (*iter == char16_t('%')) {
       ++iter;
       result |= eParseHTMLInteger_IsPercent;
@@ -4942,22 +4941,20 @@ nsContentUtils::AppendNodeTextContent(nsINode* aNode, bool aDeep,
     return static_cast<nsIContent*>(aNode)->AppendTextTo(aResult,
                                                          aFallible);
   }
-  else if (aDeep) {
+  if (aDeep) {
     return AppendNodeTextContentsRecurse(aNode, aResult, aFallible);
   }
-  else {
-    for (nsIContent* child = aNode->GetFirstChild();
-         child;
-         child = child->GetNextSibling()) {
-      if (child->IsNodeOfType(nsINode::eTEXT)) {
-        bool ok = child->AppendTextTo(aResult, fallible);
-        if (!ok) {
-            return false;
-        }
+
+  for (nsIContent* child = aNode->GetFirstChild();
+       child;
+       child = child->GetNextSibling()) {
+    if (child->IsNodeOfType(nsINode::eTEXT)) {
+      bool ok = child->AppendTextTo(aResult, fallible);
+      if (!ok) {
+        return false;
       }
     }
   }
-
   return true;
 }
 
@@ -5756,9 +5753,8 @@ nsContentUtils::GetCurrentJSContextForThread()
   MOZ_ASSERT(IsInitialized());
   if (MOZ_LIKELY(NS_IsMainThread())) {
     return GetCurrentJSContext();
-  } else {
-    return workers::GetCurrentThreadJSContext();
   }
+  return workers::GetCurrentThreadJSContext();
 }
 
 template<typename StringType, typename CharType>
@@ -8690,9 +8686,11 @@ nsContentUtils::InternalStorageAllowedForPrincipal(nsIPrincipal* aPrincipal,
   permissionManager->TestPermissionFromPrincipal(aPrincipal, "cookie", &perm);
   if (perm == nsIPermissionManager::DENY_ACTION) {
     return StorageAccess::eDeny;
-  } else if (perm == nsICookiePermission::ACCESS_SESSION) {
+  }
+  if (perm == nsICookiePermission::ACCESS_SESSION) {
     return std::min(access, StorageAccess::eSessionScoped);
-  } else if (perm == nsIPermissionManager::ALLOW_ACTION) {
+  }
+  if (perm == nsIPermissionManager::ALLOW_ACTION) {
     return access;
   }
 
diff --git a/dom/base/nsDOMWindowUtils.cpp b/dom/base/nsDOMWindowUtils.cpp
index bef0f96d807f..68f61f95096f 100644
--- a/dom/base/nsDOMWindowUtils.cpp
+++ b/dom/base/nsDOMWindowUtils.cpp
@@ -3707,10 +3707,8 @@ nsDOMWindowUtils::GetOMTAStyle(nsIDOMElement* aElement,
     cssValue->GetCssText(text, rv);
     aResult.Assign(text);
     return rv.StealNSResult();
-  } else {
-    aResult.Truncate();
   }
-
+  aResult.Truncate();
   return NS_OK;
 }
 
diff --git a/dom/base/nsFrameMessageManager.cpp b/dom/base/nsFrameMessageManager.cpp
index ebccf50c8598..1520dd882da9 100644
--- a/dom/base/nsFrameMessageManager.cpp
+++ b/dom/base/nsFrameMessageManager.cpp
@@ -802,9 +802,8 @@ nsFrameMessageManager::PrivateNoteIntentionalCrash()
   if (XRE_IsContentProcess()) {
     mozilla::NoteIntentionalCrash("tab");
     return NS_OK;
-  } else {
-    return NS_ERROR_NOT_IMPLEMENTED;
   }
+  return NS_ERROR_NOT_IMPLEMENTED;
 }
 
 NS_IMETHODIMP
diff --git a/dom/base/nsGlobalWindow.cpp b/dom/base/nsGlobalWindow.cpp
index f379dcac707b..27a54099e13a 100644
--- a/dom/base/nsGlobalWindow.cpp
+++ b/dom/base/nsGlobalWindow.cpp
@@ -6825,13 +6825,12 @@ MakeWidgetFullscreen(nsGlobalWindow* aWindow, FullscreenReason aReason,
   // most of the widget will be selected.
   if (!performTransition) {
     return aWindow->SetWidgetFullscreen(aReason, aFullscreen, widget, nullptr);
-  } else {
-    nsCOMPtr<nsIRunnable> task =
-      new FullscreenTransitionTask(duration, aWindow, aFullscreen,
-                                   widget, nullptr, transitionData);
-    task->Run();
-    return true;
   }
+  nsCOMPtr<nsIRunnable> task =
+    new FullscreenTransitionTask(duration, aWindow, aFullscreen,
+                                 widget, nullptr, transitionData);
+  task->Run();
+  return true;
 }
 
 nsresult
@@ -14550,10 +14549,9 @@ nsGlobalWindow::CreateImageBitmap(const ImageBitmapSource& aImage,
   if (aImage.IsArrayBuffer() || aImage.IsArrayBufferView()) {
     return ImageBitmap::Create(this, aImage, aOffset, aLength, aFormat, aLayout,
                                aRv);
-  } else {
-    aRv.Throw(NS_ERROR_TYPE_ERR);
-    return nullptr;
   }
+  aRv.Throw(NS_ERROR_TYPE_ERR);
+  return nullptr;
 }
 
 // Helper called by methods that move/resize the window,
diff --git a/dom/base/nsImageLoadingContent.cpp b/dom/base/nsImageLoadingContent.cpp
index ad9c8dad30c3..02b28b6a13d2 100644
--- a/dom/base/nsImageLoadingContent.cpp
+++ b/dom/base/nsImageLoadingContent.cpp
@@ -1392,11 +1392,11 @@ nsImageLoadingContent::GetRegisteredFlagForRequest(imgIRequest* aRequest)
 {
   if (aRequest == mCurrentRequest) {
     return &mCurrentRequestRegistered;
-  } else if (aRequest == mPendingRequest) {
-    return &mPendingRequestRegistered;
-  } else {
-    return nullptr;
   }
+  if (aRequest == mPendingRequest) {
+    return &mPendingRequestRegistered;
+  }
+  return nullptr;
 }
 
 void
diff --git a/dom/base/nsObjectLoadingContent.cpp b/dom/base/nsObjectLoadingContent.cpp
index 0c8144d9113c..f81f5d4e4a58 100644
--- a/dom/base/nsObjectLoadingContent.cpp
+++ b/dom/base/nsObjectLoadingContent.cpp
@@ -237,7 +237,8 @@ CheckPluginStopEvent::Run()
       LOG(("OBJLC [%p]: CheckPluginStopEvent - superseded in layout flush",
            this));
       return NS_OK;
-    } else if (content->GetPrimaryFrame()) {
+    }
+    if (content->GetPrimaryFrame()) {
       LOG(("OBJLC [%p]: CheckPluginStopEvent - frame gained in layout flush",
            this));
       objLC->mPendingCheckPluginStopEvent = nullptr;
@@ -1033,10 +1034,9 @@ nsObjectLoadingContent::OnStartRequest(nsIRequest *aRequest,
     }
     if (MakePluginListener()) {
       return mFinalListener->OnStartRequest(aRequest, nullptr);
-    } else {
-      NS_NOTREACHED("Failed to create PluginStreamListener, aborting channel");
-      return NS_BINDING_ABORTED;
     }
+    NS_NOTREACHED("Failed to create PluginStreamListener, aborting channel");
+    return NS_BINDING_ABORTED;
   }
 
   // Otherwise we should be state loading, and call LoadObject with the channel
@@ -1069,7 +1069,8 @@ nsObjectLoadingContent::OnStartRequest(nsIRequest *aRequest,
     Telemetry::Accumulate(Telemetry::PLUGIN_BLOCKED_FOR_STABILITY, 1);
     mContentBlockingEnabled = true;
     return NS_ERROR_FAILURE;
-  } else if (status == NS_ERROR_TRACKING_URI) {
+  }
+  if (status == NS_ERROR_TRACKING_URI) {
     mContentBlockingEnabled = true;
     return NS_ERROR_FAILURE;
   }