Initializing arrays in kotlin

Question

I am making a haiku generator in kotlin but I am getting a weird 'variable firstLineArray must be initialized' on this block of code.

import java.util.Random

fun oneSyllableWords() : String{
    val oneSyllableWordArray = arrayOf("Life", "Love", "One", "On", "No", "Go")
    val random = Random()
    val randint = random.nextInt(oneSyllableWordArray.size)
    return oneSyllableWordArray[randint]
}

fun main(args:Array<String>){
    var firstLineArray : Array<String>
    var syllablesRemaining = 5
    while(syllablesRemaining<0) {
        val random = Random()
        val randint = random.nextInt(4) + 1
        for (i in 0..4){
            if(randint == 1){
                firstLineArray[i] = oneSyllableWords()
            }
        }
    }
}

zsmb13 · Accepted Answer · 2017-05-29 14:36:58Z

9

You have to initialize your variable with a value. Arrays are fixed size containers, if I'm right that you need an array with a length of 5 here, you can use the following to create it with 5 empty strings as a start:

var firstLineArray: Array<String> = Array(5) { "" }

Or if you're okay with having an Array<String?> and having to deal with possible null values when reading from the array, you can do:

var firstLineArray: Array<String?> = arrayOfNulls(5)

answered May 29, 2017 at 14:36

zsmb13

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Comments

developer_hatch · Accepted Answer · 2017-05-29 14:33:48Z

3

you forget init the array:

Ways:

var firstLineArray = Array<String>()

or

var firstLineArray = Array (0, { i -> "" })

or

var firstLineArray = emptyArray<String>()

answered May 29, 2017 at 14:33

developer_hatch

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Comments

Avijit Karmakar · Accepted Answer · 2017-05-29 16:08:07Z

2

You can initialize a String array by the below code:

var firstLineArray = arrayOfNulls<String>(5)

The above code will give a String array containing null. It returns Array<String?>

var firstLineArray = Array<String>(5) { "it = $it" } // returns Array<String>

var firstLineArray = arrayOf("a", "b", "c", "d", "e") // returns Array<String>

answered May 29, 2017 at 16:08

Avijit Karmakar

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Comments

Bhanu Prakash Pasupula · Accepted Answer · 2018-06-06 18:02:11Z

0

val read = Scanner(System.'in')
print("Enter length: ")
val length = read.nextInt()
var arry: Array<Int> = Array(length){0}

for(i in 1..length-1){
arry[i] = read.nextInt()
}

To read the int values from the input and store the Array as integers

answered Jun 6, 2018 at 18:02

Bhanu Prakash Pasupula

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