Bangladeshi Android App Contributors

  Kotlin Function function means use big problems divided by submodule and easily problems solved.   It makes reusability of code and makes the program more manageable There are two types of functions: Standard library function User-defined function Standard Library Function Kotlin Standard library function is built-in library functions import java.time.LocalDateTime fun main (args: Array < String >) { val current = LocalDateTime.now() println( "Current Date and Time is: $current " ) } User-defined Function A user-defined is created by the user. User-defined function takes the parameter(s), perform an action and return the result of that action as a value. fun  main(args: Array<String>){       sum()       print( "code after sum" )   }   fun  sum(){       var num1 = 5        var num2 =  6        println( "sum = " +(num1+num2))   }   paremetarize function :  fun  main(args: Array<String>){      val result = sum( 5 ,  6 )     

kotline Basic type (Datatype) /* fun main() { print("hellow first main function") } */ fun main ( args: Array<String> ) { /* data type in kotlin */ //---number data type-- var b : Byte = 111 var s : Short = 11111 var i : Int = 1111111111 var f : Float = 1.00f var d : Double = 1.00 var l : Long = 1111111111111111111 var charactervalue : Char = 'c' var Stringvalue : String = "stringvalue" var flag : Boolean = true println ( "byte---8-bit : " + b ) println ( "short---16-bit : " + s ) println ( "int---32-bit : " + i ) println ( "float---32-bit : " + f ) println ( "double---64-bit : " + d ) println ( "long---64-bit : " + l ) println ( "char---: " + charactervalue ) println ( "Strin---: " + Stringvalue ) println ( "boolean---: " + flag ) var name : String name = "r

 All Collection Type Details  in Kotlin fun main ( args: Array<String> ) { /* collectin of Two Types 1.immutable (immutable means : Collection only Read) 2.Mutable (Mutable means : Collection Read and Write) */ /* 1.immutable collection: 1.listof 2.mapof 3.setof */ val idlistof = listOf <Int> ( 1 , 1 , 1 , 1 ) val idlistof_without_type = listOf ( 1 , 1 , 1 , 1 ) val idmapof = mapOf <String, String> ( "1" to "ruhul" , "2" to "amin" ) val idmapof_without_type = mapOf ( "1" to "ruhul" , "2" to "amin" ) val idmapof_defrentdata_without_type = mapOf ( "1" to "ruhul" , 2 to "amin" ) val setof = setOf <String> ( "Asia" , "Urop" ) val idsetof_without_type = setOf ( "Asia" , "Urop" ) /* 1.mutable collection: 1.mutable list 1.

 kotlin Array Types import com.sun.xml.internal.fastinfoset.util. StringArray import java.util.* fun main () { /* scanner object*/ val Sc = Scanner( System . `in` ) /* array in Mutable but has fixed size */ /*array declaration system */ val idvalue = Array <Int> ( 5 ) { 0 } for ( i in idvalue . indices ) { println ( "please input value [ $ i ] = " ) idvalue [ i ] = Sc .nextInt() } for ( v in idvalue ) { println ( v ) } /* array declaration two type: 1.explicit 2.implicit */ /* explicit type declaration*/ val language = arrayOf <String> ( "kotlin" , "java" , "php" , "python" ) language .set( 0 , "java" ) language .set( 1 , "kotlin" ) println ( "language [0]=" + language .get( 0 )) println ( "language [1]=" + language .get( 1 )) for ( values in language ) { println ( &q

 var val  deference in kotlin  fun main () { var Android_Programing_language : String = "java" println ( "android official programing language: " + Android_Programing_language ) Android_Programing_language = "Kotline" println ( "2019 google announced android official programing language: " + Android_Programing_language ) val Android_MultiPlatform_language : String = "Dart" println ( "multiple device run : " + Android_MultiPlatform_language ) /* Android_MultiPlatform_language="" /* note: var--------------valu changable note: val--------------valu not changable (final) */ */ }