diff --git a/core-java/src/main/java/com/baeldung/optionalparams/MultiVitamin.java b/core-java/src/main/java/com/baeldung/optionalparams/MultiVitamin.java
new file mode 100644
index 0000000000..709e74eac0
--- /dev/null
+++ b/core-java/src/main/java/com/baeldung/optionalparams/MultiVitamin.java
@@ -0,0 +1,50 @@
+package com.baeldung.optionalparams;
+
+public class MultiVitamin {
+
+    private String name;    // required
+    private int vitaminA;   // in mcg
+    private int vitaminC;   // in mg
+    private int calcium;    // in mg
+    private int iron;       // in mg
+
+    public MultiVitamin(String name) {
+        this.name = name;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public int getVitaminA() {
+        return vitaminA;
+    }
+
+    public void setVitaminA(int vitaminA) {
+        this.vitaminA = vitaminA;
+    }
+
+    public int getVitaminC() {
+        return vitaminC;
+    }
+
+    public void setVitaminC(int vitaminC) {
+        this.vitaminC = vitaminC;
+    }
+
+    public int getCalcium() {
+        return calcium;
+    }
+
+    public void setCalcium(int calcium) {
+        this.calcium = calcium;
+    }
+
+    public int getIron() {
+        return iron;
+    }
+
+    public void setIron(int iron) {
+        this.iron = iron;
+    }
+}
\ No newline at end of file
diff --git a/core-java/src/main/java/com/baeldung/optionalparams/MultiVitaminAllowingNulls.java b/core-java/src/main/java/com/baeldung/optionalparams/MultiVitaminAllowingNulls.java
new file mode 100644
index 0000000000..36d178783a
--- /dev/null
+++ b/core-java/src/main/java/com/baeldung/optionalparams/MultiVitaminAllowingNulls.java
@@ -0,0 +1,38 @@
+package com.baeldung.optionalparams;
+
+public class MultiVitaminAllowingNulls {
+
+    private String name;    // required
+    private Integer vitaminA;   // in mcg
+    private Integer vitaminC;   // in mg
+    private Integer calcium;    // in mg
+    private Integer iron;       // in mg
+
+    public MultiVitaminAllowingNulls(String name, Integer vitaminA, Integer vitaminC, Integer calcium, Integer iron) {
+        this.name = name;
+        this.vitaminA = vitaminA;
+        this.vitaminC = vitaminC;
+        this.calcium = calcium;
+        this.iron = iron;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public Integer getVitaminA() {
+        return vitaminA;
+    }
+
+    public Integer getVitaminC() {
+        return vitaminC;
+    }
+
+    public Integer getCalcium() {
+        return calcium;
+    }
+
+    public Integer getIron() {
+        return iron;
+    }
+}
\ No newline at end of file
diff --git a/core-java/src/main/java/com/baeldung/optionalparams/MultiVitaminOverloading.java b/core-java/src/main/java/com/baeldung/optionalparams/MultiVitaminOverloading.java
new file mode 100644
index 0000000000..e1d3032fd3
--- /dev/null
+++ b/core-java/src/main/java/com/baeldung/optionalparams/MultiVitaminOverloading.java
@@ -0,0 +1,56 @@
+package com.baeldung.optionalparams;
+
+public class MultiVitaminOverloading {
+
+    static final int DEFAULT_IRON_AMOUNT = 20;
+
+    private final String name;    // required
+    private final int vitaminA;   // in mcg
+    private final int vitaminC;   // in mg
+    private final int calcium;    // in mg
+    private final int iron;       // in mg
+
+    public MultiVitaminOverloading(String name) {
+        this(name, 0);
+    }
+
+    public MultiVitaminOverloading(String name, int vitaminA) {
+        this(name, vitaminA, 0);
+    }
+
+    public MultiVitaminOverloading(String name, int vitaminA, int vitaminC) {
+        this(name, vitaminA, vitaminC, 0);
+    }
+
+    public MultiVitaminOverloading(String name, int vitaminA, int vitaminC, int calcium) {
+        this(name, vitaminA, vitaminC, calcium, DEFAULT_IRON_AMOUNT);
+    }
+
+    public MultiVitaminOverloading(String name, int vitaminA, int vitaminC, int calcium, int iron) {
+        this.name = name;
+        this.vitaminA = vitaminA;
+        this.vitaminC = vitaminC;
+        this.calcium = calcium;
+        this.iron = iron;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public int getVitaminA() {
+        return vitaminA;
+    }
+
+    public int getVitaminC() {
+        return vitaminC;
+    }
+
+    public int getCalcium() {
+        return calcium;
+    }
+
+    public int getIron() {
+        return iron;
+    }
+}
\ No newline at end of file
diff --git a/core-java/src/main/java/com/baeldung/optionalparams/MultiVitaminStaticFactoryMethods.java b/core-java/src/main/java/com/baeldung/optionalparams/MultiVitaminStaticFactoryMethods.java
new file mode 100644
index 0000000000..ca7ab0f6cf
--- /dev/null
+++ b/core-java/src/main/java/com/baeldung/optionalparams/MultiVitaminStaticFactoryMethods.java
@@ -0,0 +1,52 @@
+package com.baeldung.optionalparams;
+
+public class MultiVitaminStaticFactoryMethods {
+
+    static final int IRON_AMT_DEF = 20;
+    static final int IRON_AMT_MEN = 30;
+
+    static final int CALCIUM_AMT_DEF = 100;
+    static final int CALCIUM_AMT_WOMEN = 120;
+
+    private final String name;    // required
+    private final int vitaminA;   // in mcg
+    private final int vitaminC;   // in mg
+    private final int calcium;    // in mg
+    private final int iron;       // in mg
+
+    public static MultiVitaminStaticFactoryMethods forMen(String name) {
+        return new MultiVitaminStaticFactoryMethods(name, 5000, 60, CALCIUM_AMT_DEF, IRON_AMT_MEN);
+    }
+
+    public static MultiVitaminStaticFactoryMethods forWomen(String name) {
+        return new MultiVitaminStaticFactoryMethods(name, 5000, 60, CALCIUM_AMT_WOMEN, IRON_AMT_DEF);
+    }
+
+    private MultiVitaminStaticFactoryMethods(String name, int vitaminA, int vitaminC, int calcium, int iron) {
+        this.name = name;
+        this.vitaminA = vitaminA;
+        this.vitaminC = vitaminC;
+        this.calcium = calcium;
+        this.iron = iron;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public int getVitaminA() {
+        return vitaminA;
+    }
+
+    public int getVitaminC() {
+        return vitaminC;
+    }
+
+    public int getCalcium() {
+        return calcium;
+    }
+
+    public int getIron() {
+        return iron;
+    }
+}
\ No newline at end of file
diff --git a/core-java/src/main/java/com/baeldung/optionalparams/MultiVitaminWithBuilder.java b/core-java/src/main/java/com/baeldung/optionalparams/MultiVitaminWithBuilder.java
new file mode 100644
index 0000000000..e1b2920e9a
--- /dev/null
+++ b/core-java/src/main/java/com/baeldung/optionalparams/MultiVitaminWithBuilder.java
@@ -0,0 +1,77 @@
+package com.baeldung.optionalparams;
+
+public class MultiVitaminWithBuilder {
+
+    private final String name;    // required
+    private final int vitaminA;   // in mcg
+    private final int vitaminC;   // in mg
+    private final int calcium;    // in mg
+    private final int iron;       // in mg
+
+    private MultiVitaminWithBuilder(MultiVitaminBuilder builder) {
+        this.name = builder.name;
+        this.vitaminA = builder.vitaminA;
+        this.vitaminC = builder.vitaminC;
+        this.calcium = builder.calcium;
+        this.iron = builder.iron;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public int getVitaminA() {
+        return vitaminA;
+    }
+
+    public int getVitaminC() {
+        return vitaminC;
+    }
+
+    public int getCalcium() {
+        return calcium;
+    }
+
+    public int getIron() {
+        return iron;
+    }
+
+    public static class MultiVitaminBuilder {
+
+        private static final int ZERO = 0;
+
+        private final String name; // required
+        private int vitaminA = ZERO;
+        private int vitaminC = ZERO;
+        private int calcium = ZERO;
+        private int iron = ZERO;
+
+        public MultiVitaminBuilder(String name) {
+            this.name = name;
+        }
+
+        public MultiVitaminBuilder withVitaminA(int vitaminA) {
+            this.vitaminA = vitaminA;
+            return this;
+        }
+
+        public MultiVitaminBuilder withVitaminC(int vitaminC) {
+            this.vitaminC = vitaminC;
+            return this;
+        }
+
+        public MultiVitaminBuilder withCalcium(int calcium) {
+            this.calcium = calcium;
+            return this;
+        }
+
+        public MultiVitaminBuilder withIron(int iron) {
+            this.iron = iron;
+            return this;
+        }
+
+        public MultiVitaminWithBuilder build() {
+            return new MultiVitaminWithBuilder(this);
+        }
+    }
+}
diff --git a/core-java/src/test/java/com/baeldung/optionalparams/OptionalParamsUnitTest.java b/core-java/src/test/java/com/baeldung/optionalparams/OptionalParamsUnitTest.java
new file mode 100644
index 0000000000..4f3c31822b
--- /dev/null
+++ b/core-java/src/test/java/com/baeldung/optionalparams/OptionalParamsUnitTest.java
@@ -0,0 +1,96 @@
+package com.baeldung.optionalparams;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.math.BigDecimal;
+
+import org.assertj.core.util.Arrays;
+import org.junit.Test;
+
+public class OptionalParamsUnitTest {
+
+    @Test
+    public void whenCreateMultiVitaminWithOverloading_thenOk() {
+        MultiVitaminOverloading multiVitamin = new MultiVitaminOverloading("Default Multivitamin");
+
+        assertThat(multiVitamin.getName()).isEqualTo("Default Multivitamin");
+        assertThat(multiVitamin.getVitaminA()).isEqualTo(0);
+        assertThat(multiVitamin.getVitaminC()).isEqualTo(0);
+        assertThat(multiVitamin.getCalcium()).isEqualTo(0);
+        assertThat(multiVitamin.getIron()).isEqualTo(MultiVitaminOverloading.DEFAULT_IRON_AMOUNT);
+    }
+
+    @Test
+    public void whenCreateMultiVitaminWithStaticFactoryMethods_thenOk() {
+        MultiVitaminStaticFactoryMethods mensMultiVitamin = MultiVitaminStaticFactoryMethods.forMen("Complete for Men");
+
+        assertThat(mensMultiVitamin.getName()).isEqualTo("Complete for Men");
+        assertThat(mensMultiVitamin.getCalcium()).isEqualTo(MultiVitaminStaticFactoryMethods.CALCIUM_AMT_DEF);
+        assertThat(mensMultiVitamin.getIron()).isEqualTo(MultiVitaminStaticFactoryMethods.IRON_AMT_MEN);
+
+        MultiVitaminStaticFactoryMethods womensMultiVitamin = MultiVitaminStaticFactoryMethods.forWomen("Complete for Women");
+
+        assertThat(womensMultiVitamin.getName()).isEqualTo("Complete for Women");
+        assertThat(womensMultiVitamin.getCalcium()).isEqualTo(MultiVitaminStaticFactoryMethods.CALCIUM_AMT_WOMEN);
+        assertThat(womensMultiVitamin.getIron()).isEqualTo(MultiVitaminStaticFactoryMethods.IRON_AMT_DEF);
+    }
+
+    @Test
+    public void whenCreateMultiVitaminWithBuilder_thenOk() {
+        MultiVitaminWithBuilder vitamin = new MultiVitaminWithBuilder.MultiVitaminBuilder("Maximum Strength")
+          .withCalcium(100)
+          .withIron(200)
+          .withVitaminA(50)
+          .withVitaminC(1000)
+          .build();
+
+        assertThat(vitamin.getName()).isEqualTo("Maximum Strength");
+        assertThat(vitamin.getCalcium()).isEqualTo(100);
+        assertThat(vitamin.getIron()).isEqualTo(200);
+        assertThat(vitamin.getVitaminA()).isEqualTo(50);
+        assertThat(vitamin.getVitaminC()).isEqualTo(1000);
+    }
+
+    @Test
+    public void whenCreateMutliVitaminWithAccessors_thenOk() {
+        MultiVitamin vitamin = new MultiVitamin("Generic");
+        vitamin.setVitaminA(50);
+        vitamin.setVitaminC(1000);
+        vitamin.setCalcium(100);
+        vitamin.setIron(200);
+
+        assertThat(vitamin.getName()).isEqualTo("Generic");
+        assertThat(vitamin.getCalcium()).isEqualTo(100);
+        assertThat(vitamin.getIron()).isEqualTo(200);
+        assertThat(vitamin.getVitaminA()).isEqualTo(50);
+        assertThat(vitamin.getVitaminC()).isEqualTo(1000);
+    }
+
+    @Test
+    public void whenCreateMultiVitaminWithNulls_thenOk() {
+        MultiVitamin vitamin = new MultiVitamin(null);
+
+        assertThat(vitamin.getName()).isNull();
+    }
+
+    public void varArgsDemo() {
+        Object[] args = Arrays.array(Long.valueOf(1), Integer.valueOf(2), BigDecimal.valueOf(3));
+
+        processVarArgsWithCastingAntiPattern(args);
+    }
+
+    private void processVarArgsWithCastingAntiPattern(Object... args) {
+        String message = "processing %s as %s";
+
+        // never do this sort of thing
+        for (Object arg : args) {
+            if (arg instanceof Long) {
+                System.out.println(String.format(message, arg, "Long"));
+            } else if (arg instanceof Integer) {
+                System.out.println(String.format(message, arg, "Integer"));
+            } else if (arg instanceof BigDecimal) {
+                System.out.println(String.format(message, arg, "BigDecimal"));
+            }
+        }
+    }
+}