YugandharVadlamudi

Interview Questions

Kotlin

Q1: What is a primary constructor in Kotlin? ☆☆

Answer: The primary constructor is part of the class header. Unlike Java, you don't need to declare a constructor in the body of the class. Here's an example:

YugandharVadlamudi

# To enable ProGuard in your project, edit project.properties
# to define the proguard.config property as described in that file.
#
# Add project specific ProGuard rules here.
# By default, the flags in this file are appended to flags specified
# in ${sdk.dir}/tools/proguard/proguard-android.txt
# You can edit the include path and order by changing the ProGuard
# include property in project.properties.
#
# For more details, see

YugandharVadlamudi

import android.util.Log;

import com.appandweb.prjtestdrivendev.BuildConfig;
import com.squareup.okhttp.Interceptor;
import com.squareup.okhttp.Request;
import com.squareup.okhttp.Response;
import com.squareup.okhttp.ResponseBody;

import java.io.IOException;

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fun main(args: Array<String>) {
//    Pair Example with infix notation
    var pairExample = 1 to 3
    println("${pairExample.second}")
//    pair with object notation
    var pairExampleObj = Pair(3, 4)
    println("the value be ${pairExampleObj.first}")

}
###Output###

YugandharVadlamudi

fun main(args: Array<String>) {

//To accept any datatype we have to use Any datatype
    var anyDatatype: Any = 1  //it is accepting Int
    println("the value is ${anyDatatype} ")
    anyDatatype="Hello" // it is accepting String
    println("the value is ${anyDatatype} ")

}
###Output###

YugandharVadlamudi

fun main(args: Array<String>) {
//    here there is not Datatype deceleration
    var check = "Hello"
    var number = 1
    println("the value of check ${check} \n ${number}")
            
//    if infered type is done then we can not change it's datatype
//    number="String" //Error

YugandharVadlamudi

fun main(args: Array<String>) {
val hello = "hello"
//value can not be reinitialized because it is like final variable in java 
    hello = "dlkjf" // it will produce an compile time error
    println("$hello")
}
###output###
hello

YugandharVadlamudi

fun main(args: Array<String>) {
//var variable is decleared 
var name = "name Check"
    println(name)
    //changed the value of the variable
    name="hell"
     println("name is $name" + " check ")
}
###output###
name Check

YugandharVadlamudi

class DemoConstructorOverload
{
  /**
*Constructor means method name is  same as classname and no return type 
*DemoConstructorOverload() is constructo
*/
  DemoConstructoroverload()
{
    System.out.println("hello default constructor");
} 

YugandharVadlamudi

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_animation_on_click_test"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.compindia.viewstateanimationapp.AnimationOnClickTestActivity">