Kotlin Builder example refactor (#4895)

* encoding

* Refactor builder

* Usage

* Builder as data class

core-kotlin/src/main/kotlin/com/baeldung/builder/FoodOrder.kt

@@ -1,39 +1,22 @@
 package com.baeldung.builder
 
-class FoodOrder private constructor(builder: FoodOrder.Builder) {
-
-    val bread: String?
-    val condiments: String?
-    val meat: String?
-    val fish: String?
-
-    init {
-        this.bread = builder.bread
-        this.condiments = builder.condiments
-        this.meat = builder.meat
-        this.fish = builder.fish
-    }
-
-    class Builder {
-
-        var bread: String? = null
-            private set
-        var condiments: String? = null
-            private set
-        var meat: String? = null
-            private set
-        var fish: String? = null
-            private set
+class FoodOrder(
+  val bread: String?,
+  val condiments: String?,
+  val meat: String?,
+  val fish: String?
+) {
+    data class Builder(
+      var bread: String? = null,
+      var condiments: String? = null,
+      var meat: String? = null,
+      var fish: String? = null) {
 
         fun bread(bread: String) = apply { this.bread = bread }
-
         fun condiments(condiments: String) = apply { this.condiments = condiments }
-
         fun meat(meat: String) = apply { this.meat = meat }
-
         fun fish(fish: String) = apply { this.fish = fish }
-
-        fun build() = FoodOrder(this)
-
+        fun build() = FoodOrder(bread, condiments, meat, fish)
     }
 }
+

core-kotlin/src/main/kotlin/com/baeldung/builder/FoodOrderNamed.kt

@@ -1,7 +1,7 @@
 package com.baeldung.builder
 
 data class FoodOrderNamed(
-        val bread: String? = null,
-        val condiments: String? = null,
-        val meat: String? = null,
-        val fish: String? = null)
+  val bread: String? = null,
+  val condiments: String? = null,
+  val meat: String? = null,
+  val fish: String? = null)

core-kotlin/src/main/kotlin/com/baeldung/builder/Main.kt

@@ -0,0 +1,9 @@
+package com.baeldung.builder
+
+fun main(args: Array<String>) {
+    FoodOrder.Builder()
+      .bread("bread")
+      .condiments("condiments")
+      .meat("meat")
+      .fish("bread").let { println(it) }
+}