diff --git a/java-checks/src/main/java/org/sonar/java/checks/DateTimeConversionsCheck.java b/java-checks/src/main/java/org/sonar/java/checks/DateTimeConversionsCheck.java
index f7fee6daeee..fd773757418 100644
--- a/java-checks/src/main/java/org/sonar/java/checks/DateTimeConversionsCheck.java
+++ b/java-checks/src/main/java/org/sonar/java/checks/DateTimeConversionsCheck.java
@@ -99,12 +99,10 @@ private static boolean isLocalDateOrTime(Type type) {
   private static ExpressionTree skipParenthesesAndCasts(ExpressionTree expression) {
     ExpressionTree result = expression;
     while (true) {
-      if (result instanceof ParenthesizedTree parenthesizedTree) {
-        result = parenthesizedTree.expression();
-      } else if (result instanceof TypeCastTree typeCastTree) {
-        result = typeCastTree.expression();
-      } else {
-        return result;
+      switch (result) {
+        case ParenthesizedTree parenthesizedTree -> result = parenthesizedTree.expression();
+        case TypeCastTree typeCastTree -> result = typeCastTree.expression();
+        default -> { return result; }
       }
     }
   }
diff --git a/java-checks/src/main/java/org/sonar/java/checks/PatternMatchUsingIfCheck.java b/java-checks/src/main/java/org/sonar/java/checks/PatternMatchUsingIfCheck.java
index ce1d538a9cb..46dd997a0c1 100644
--- a/java-checks/src/main/java/org/sonar/java/checks/PatternMatchUsingIfCheck.java
+++ b/java-checks/src/main/java/org/sonar/java/checks/PatternMatchUsingIfCheck.java
@@ -217,18 +217,20 @@ private JavaQuickFix computeQuickFix(List<Case> cases, IfStatementTree topLevelI
   }
 
   private void writeCase(Case caze, StringBuilder sb, int baseIndent, boolean canLiftReturn) {
-    if (caze instanceof PatternMatchCase patternMatchCase) {
-      sb.append("case ").append(QuickFixHelper.contentForTree(patternMatchCase.pattern, context));
-      if (!patternMatchCase.guards().isEmpty()) {
-        List<ExpressionTree> guards = patternMatchCase.guards();
-        sb.append(" when ");
-        join(guards, " && ", sb);
+    switch (caze) {
+      case PatternMatchCase patternMatchCase -> {
+        sb.append("case ").append(QuickFixHelper.contentForTree(patternMatchCase.pattern, context));
+        if (!patternMatchCase.guards().isEmpty()) {
+          List<ExpressionTree> guards = patternMatchCase.guards();
+          sb.append(" when ");
+          join(guards, " && ", sb);
+        }
       }
-    } else if (caze instanceof EqualityCase equalityCase) {
-      sb.append("case ");
-      join(equalityCase.constants, ", ", sb);
-    } else {
-      sb.append("default");
+      case EqualityCase equalityCase -> {
+        sb.append("case ");
+        join(equalityCase.constants, ", ", sb);
+      }
+      case DefaultCase ignored -> sb.append("default");
     }
     sb.append(" -> ");
     if (canLiftReturn) {
diff --git a/java-checks/src/main/java/org/sonar/java/checks/TryWithResourcesCheck.java b/java-checks/src/main/java/org/sonar/java/checks/TryWithResourcesCheck.java
index 5696f4be99f..d85cf3cd341 100644
--- a/java-checks/src/main/java/org/sonar/java/checks/TryWithResourcesCheck.java
+++ b/java-checks/src/main/java/org/sonar/java/checks/TryWithResourcesCheck.java
@@ -97,15 +97,13 @@ public void visitNode(Tree tree) {
   }
 
   private static boolean isNewAutocloseableOrBuilder(Tree tree, JavaFileScannerContext context) {
-    if (tree instanceof NewClassTree newClass) {
-      return newClass.symbolType().isSubtypeOf("java.lang.AutoCloseable");
-    } else if (tree instanceof MethodInvocationTree mit) {
-      return AUTOCLOSEABLE_FACTORY_MATCHER.matches(mit) ||
+    return switch (tree) {
+      case NewClassTree newClass -> newClass.symbolType().isSubtypeOf("java.lang.AutoCloseable");
+      case MethodInvocationTree mit -> AUTOCLOSEABLE_FACTORY_MATCHER.matches(mit) ||
         (context.getJavaVersion().isJava21Compatible() && AUTOCLOSEABLE_JAVA21_MATCHER.matches(mit)) ||
         (context.getJavaVersion().isJava26Compatible() && AUTOCLOSEABLE_JAVA26_MATCHER.matches(mit));
-    } else {
-      return false;
-    }
+      default -> false;
+    };
   }
 
   private static boolean isFollowedByTryWithFinally(Tree tree) {
diff --git a/java-checks/src/main/java/org/sonar/java/checks/helpers/StringUtils.java b/java-checks/src/main/java/org/sonar/java/checks/helpers/StringUtils.java
index 2c2e755afcb..9def709ec63 100644
--- a/java-checks/src/main/java/org/sonar/java/checks/helpers/StringUtils.java
+++ b/java-checks/src/main/java/org/sonar/java/checks/helpers/StringUtils.java
@@ -60,14 +60,11 @@ public static int countMatches(@Nullable String string, @Nullable String pattern
   public static String[] flatten(Object ... args) {
     List<String> result = new ArrayList<>();
     for (Object arg : args) {
-      if (arg instanceof String s) {
-        result.add(s);
-      } else if (arg instanceof String[] arr) {
-        Collections.addAll(result, arr);
-      } else if (arg instanceof Collection<?> col) {
-        result.addAll((Collection<String>) col);
-      } else {
-        throw new IllegalArgumentException("Unsupported argument type: " + arg.getClass());
+      switch (arg) {
+        case String s -> result.add(s);
+        case String[] arr -> Collections.addAll(result, arr);
+        case Collection<?> col -> result.addAll((Collection<String>) col);
+        default -> throw new IllegalArgumentException("Unsupported argument type: " + arg.getClass());
       }
     }
     return result.toArray(new String[0]);
diff --git a/java-frontend/src/main/java/org/sonar/java/model/JSymbolMetadata.java b/java-frontend/src/main/java/org/sonar/java/model/JSymbolMetadata.java
index 2b9c5b6b862..c147437bf67 100644
--- a/java-frontend/src/main/java/org/sonar/java/model/JSymbolMetadata.java
+++ b/java-frontend/src/main/java/org/sonar/java/model/JSymbolMetadata.java
@@ -263,16 +263,12 @@ private static Symbol getEffectiveOwner(Symbol symbol, NullabilityLevel currentL
   }
 
   private static NullabilityLevel getLevel(Symbol symbol) {
-    if (symbol.isVariableSymbol()) {
-      return NullabilityLevel.VARIABLE;
-    } else if (symbol.isMethodSymbol()) {
-      return NullabilityLevel.METHOD;
-    } else if (symbol.isTypeSymbol()) {
-      return NullabilityLevel.CLASS;
-    } else if (symbol.isPackageSymbol()) {
-      return NullabilityLevel.PACKAGE;
-    }
-    return NullabilityLevel.UNKNOWN;
+    return switch (symbol) {
+      case Symbol.VariableSymbol v -> NullabilityLevel.VARIABLE;
+      case Symbol.MethodSymbol m -> NullabilityLevel.METHOD;
+      case Symbol.TypeSymbol t -> NullabilityLevel.CLASS;
+      default -> symbol.isPackageSymbol() ? NullabilityLevel.PACKAGE : NullabilityLevel.UNKNOWN;
+    };
   }
 
   @CheckForNull