What s the Kotlin equivalent of Java s String

Question

I see that Kotlin has ByteArray  ShortArray  IntArray  CharArray  DoubleArray  FloatArray  which are equivalent to byte    short    int   char    double    float   in Java   Now I m wondering  is there any StringArray equivalent to Java s String

User · Answer

To create an empty Array of Strings in Kotlin you should use one of the following six approaches:

First approach:

val empty = arrayOf<String>()

Second approach:

val empty = arrayOf("","","")

Third approach:

val empty = Array<String?>(3) { null }

Fourth approach:

val empty = arrayOfNulls<String>(3)

Fifth approach:

val empty = Array<String>(3) { "it = $it" }

Sixth approach:

val empty = Array<String>(0, { _ -> "" })

User · Answer

This example works perfectly in Android  In kotlin you can use a lambda expression for this  The Kotlin Array Constructor definition is   Array size  Int  init   Int  - gt  T    Which evaluates to   skillsSummaryDetailLinesArray   Array linesLen            i  Int - gt  skillsSummaryDetailLines   getString i      Or   skillsSummaryDetailLinesArray   Array lt String gt  linesLen            i  Int - gt  skillsSummaryDetailLines   getString i      In this example the field definition was   private var skillsSummaryDetailLinesArray  Array lt String gt     null   Hope this helps

User · Answer

Some of the common ways to create a String array are   var arr   Array 5        This will create an array of 5 strings with initial values to be empty string    var arr   arrayOfNulls lt String  gt  5    This will create an array of size 5 with initial values to be null  You can use String data to modify the array    var arr   arrayOf  zero    one    two    three     When you know the contents of array already then you can initialise the array directly    There is an easy way for creating an multi dimensional array of strings as well   var matrix   Array 5  Array 6         This is how you can create a matrix with 5 rows and 6 columns with initial values of  empty string

User · Answer

you can use too   val frases   arrayOf  texto01   texto02    anotherText   and      for example

User · Answer

For Strings and other types  you just use Array lt   gt   The reason IntArray and others exist is to prevent autoboxing   So int   relates to IntArray where Integer   relates to Array lt Int gt

User · Answer

use  arrayOf  arrayOfNulls  emptyArray   var colors 1  Array lt String gt    arrayOf  green    red    blue   var colors 2  Array lt String  gt    arrayOfNulls 3  var colors 3  Array lt String gt    emptyArray

User · Answer

There s no special case for String  because String is an ordinary referential type on JVM  in contrast with Java primitives  int  double       -- storing them in a reference Array lt T gt  requires boxing them into objects like Integer and Double  The purpose of specialized arrays like IntArray in Kotlin is to store non-boxed primitives  getting rid of boxing and unboxing overhead  the same as Java int   instead of Integer      You can use Array lt String gt   and Array lt String  gt  for nullables   which is equivalent to String   in Java   val stringsOrNulls   arrayOfNulls lt String gt  10     returns Array lt String  gt  val someStrings   Array lt String gt  5     it    it    val otherStrings   arrayOf  a    b    c     See also  Arrays in the language reference

User · Answer

Those types are there so that you can create arrays of the primitives  and not the boxed types  Since String isn t a primitive in Java  you can just use Array lt String gt  in Kotlin as the equivalent of a Java String

[java] What's the Kotlin equivalent of Java's String[]?

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