Implementing of classes in kotlin

Author: hussainsherwani

src/com/kotlin/oop/classes/ConstructorWitIInitBlock.kt

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+package com.kotlin.oop.classes
+
+/**
+ * Created by Hussain Sherwani
+ * at 10:42 AM on 1/9/2018
+ * [email protected] .
+ */
+class ConstructorWitIInitBlock(val name: String, var age: Int) {
+    //    val personName: String = name
+    var personAge: Int = age
+
+    init {
+        println("Object Is created")
+    }
+
+    fun speak() {
+        println("Hello Word..!")
+    }
+
+    fun great(name: String) {
+        println("Hello $name..!")
+    }
+
+    fun getYearOfBirth() = 2018 - personAge
+
+}
+fun main(args: Array<String>) {
+
+    val person = ConstructorWitIInitBlock("Hussain", 24)
+    person.speak()
+    person.great("Hussain")
+    println(person.getYearOfBirth())
+
+    println(person.name)
+    println(person.age)
+}
+

src/com/kotlin/oop/classes/Day.kt

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+package com.kotlin.oop.classes
+
+/**
+ * Created by Hussain Sherwani
+ * at 3:37 PM on 1/9/2018
+ * [email protected] .
+ */
+enum class Day {
+    MON, TUE, WED, THUR, FRI, SAT, SUN
+}

src/com/kotlin/oop/classes/EnumImplementation.kt

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+package com.kotlin.oop.classes
+
+/**
+ * Created by Hussain Sherwani
+ * at 3:40 PM on 1/9/2018
+ * [email protected] .
+ */
+fun printEnum() {
+    val currentDay : Day = Day.TUE
+
+    for (d : Day in Day.values()) {
+        println("Day: $d")
+    }
+    println("Current Day: $currentDay")
+    when (currentDay) {
+        Day.MON, Day.TUE, Day.WED, Day.THUR, Day.FRI -> println("Weekday")
+        Day.SAT, Day.SUN -> println("Weekend")
+    }
+}
+
+fun main(args: Array<String>) {
+    printEnum()
+}
+

src/com/kotlin/oop/classes/UserInfo.kt

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+package com.kotlin.oop.classes
+
+/**
+ * Created by Hussain Sherwani
+ * at 10:17 AM on 1/9/2018
+ * [email protected] .
+ */
+class UserInfo {
+    var name: String = "Hussain"
+    var age: Int = 23
+    fun speak() {
+        println("Hellow")
+    }
+
+    fun great(name: String) {
+        println(name)
+        println("Hello $name!")
+    }
+
+    fun greats(name: String, age: Int) {
+        println(name)
+        println("Hello $name! , your age is $age")
+    }
+//    fun getYearOfBirth(age: Int):Int{
+//        return 2017-age
+//    }
+
+    //    we can also use funcation like this.
+    fun getYearOfBirth() = 2016 - age
+}
+
+fun main(args: Array<String>) {
+    val person = UserInfo()
+
+    println(person.name)
+    println(person.age)
+    println(person.getYearOfBirth())
+//    println(person.getYearOfBirth(23))
+    person.speak()
+    person.great("Zubair")
+    person.greats("Hussain", 23)
+    person.name = "Ibrahim"
+    person.age = 18
+
+    println(person.name)
+    print(person.age)
+}

src/com/kotlin/oop/classes/UsingPrimaryConstructor.kt

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+package com.kotlin.oop.classes
+
+/**
+ * Created by Hussain Sherwani
+ * at 10:20 AM on 1/9/2018
+ * [email protected] .
+ */
+
+class UsingPrimaryConstructor(val firstName: String, var age: Int) {
+//    Here the block of code surrounded by parenthesis is the primary constructor.
+//    the constructor of this class defined two parameter one is name which is read only
+//    and other is age we can override this value
+
+}
+
+fun main(args: Array<String>) {
+
+    val person1 = UsingPrimaryConstructor("Joe", 25)
+
+    println("First Name = ${person1.firstName}")
+    println("Age = ${person1.age}")
+}
+