Merge branch 'master' into BAEL-5197/new_features_in_javav17

core-java-modules/core-java-17/src/main/java/com/baeldung/switchpatterns/GuardedPatterns.java

@@ -0,0 +1,25 @@
+package com.baeldung.switchpatterns;
+
+public class GuardedPatterns {
+
+    static double getDoubleValueUsingIf(Object o) {
+        return switch (o) {
+            case String s -> {
+                if (s.length() > 0) {
+                    yield Double.parseDouble(s);
+                } else {
+                    yield 0d;
+                }
+            }
+            default -> 0d;
+        };
+    }
+
+    static double getDoubleValueUsingGuardedPatterns(Object o) {
+        return switch (o) {
+            case String s && s.length() > 0 -> Double.parseDouble(s);
+            default -> 0d;
+        };
+    }
+
+}

core-java-modules/core-java-17/src/main/java/com/baeldung/switchpatterns/HandlingNullValues.java

@@ -0,0 +1,20 @@
+package com.baeldung.switchpatterns;
+
+public class HandlingNullValues {
+
+    static double getDoubleUsingSwitchNullCase(Object o) {
+        return switch (o) {
+            case String s -> Double.parseDouble(s);
+            case null -> 0d;
+            default -> 0d;
+        };
+    }
+
+    static double getDoubleUsingSwitchTotalType(Object o) {
+        return switch (o) {
+            case String s -> Double.parseDouble(s);
+            case Object ob -> 0d;
+        };
+    }
+
+}

core-java-modules/core-java-17/src/main/java/com/baeldung/switchpatterns/ParenthesizedPatterns.java

@@ -0,0 +1,29 @@
+package com.baeldung.switchpatterns;
+
+public class ParenthesizedPatterns {
+
+    static double getDoubleValueUsingIf(Object o) {
+        return switch (o) {
+            case String s -> {
+                if (s.length() > 0) {
+                    if (s.contains("#") || s.contains("@")) {
+                        yield 0d;
+                    } else {
+                        yield Double.parseDouble(s);
+                    }
+                } else {
+                    yield 0d;
+                }
+            }
+            default -> 0d;
+        };
+    }
+
+    static double getDoubleValueUsingParenthesizedPatterns(Object o) {
+        return switch (o) {
+            case String s && s.length() > 0 && !(s.contains("#") || s.contains("@")) -> Double.parseDouble(s);
+            default -> 0d;
+        };
+    }
+
+}

core-java-modules/core-java-17/src/main/java/com/baeldung/switchpatterns/PatternMatching.java

@@ -0,0 +1,14 @@
+package com.baeldung.switchpatterns;
+
+public class PatternMatching {
+
+    public static void main(String[] args) {
+        Object o = args[0];
+        if (o instanceof String s) {
+            System.out.printf("Object is a string %s", s);
+        } else if(o instanceof Number n) {
+            System.out.printf("Object is a number %n", n);
+        }
+    }
+
+}

core-java-modules/core-java-17/src/main/java/com/baeldung/switchpatterns/SwitchStatement.java

@@ -0,0 +1,14 @@
+package com.baeldung.switchpatterns;
+
+public class SwitchStatement {
+
+    public static void main(String[] args) {
+        final String b = "B";
+        switch (args[0]) {
+            case "A" -> System.out.println("Parameter is A");
+            case b -> System.out.println("Parameter is b");
+            default -> System.out.println("Parameter is unknown");
+        };
+    }
+
+}

core-java-modules/core-java-17/src/main/java/com/baeldung/switchpatterns/TypePatterns.java

@@ -0,0 +1,30 @@
+package com.baeldung.switchpatterns;
+
+public class TypePatterns {
+
+    static double getDoubleUsingIf(Object o) {
+        double result;
+
+        if (o instanceof Integer) {
+            result = ((Integer) o).doubleValue();
+        } else if (o instanceof Float) {
+            result = ((Float) o).doubleValue();
+        } else if (o instanceof String) {
+            result = Double.parseDouble(((String) o));
+        } else {
+            result = 0d;
+        }
+
+        return result;
+    }
+
+    static double getDoubleUsingSwitch(Object o) {
+        return switch (o) {
+            case Integer i -> i.doubleValue();
+            case Float f -> f.doubleValue();
+            case String s -> Double.parseDouble(s);
+            default -> 0d;
+        };
+    }
+
+}