Can't access variable in data class kotlin

Question

why can't I access a variable from another class? (the variable is in the data class, and when I want to access it, it throws "unresolved reference")

Here's what It looks like:

The code that tries to access the variable:


import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.widget.TextView

class questionActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_question)
        var nameDisplay: TextView = findViewById(R.id.nameDisplay)
        var name2 = usernameStore.username //here's the error, the "username" thing is red
        nameDisplay.setText(name2)

    }
}

The data Class:

package com.ketchup.myquizzies

public data class usernameStore (
   var username: String
)

Any help appreciated guys, I literally searched all things that came to my mind to solve this, but I couldn't help myself :(

Android Studio, Kotlin

CommonsWare · Accepted Answer · 2023-01-28 23:48:21Z

3

usernameStore is a class, not an object. You need to create an instance of usernameStore to be able to use it.

class questionActivity : AppCompatActivity() {
    val store = usernameStore()

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_question)
        var nameDisplay: TextView = findViewById(R.id.nameDisplay)
        var name2 = store.username
        nameDisplay.setText(name2)

    }
}

FWIW, creating instances of classes is covered by this section of this chapter of this free book.

answered Jan 28, 2023 at 23:48

CommonsWare

1.0m195 gold badges2.4k silver badges2.7k bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Arnaldo Over a year ago

Also: remember: Class names must be mixed case, with the first letter of each inner word capitalized (CamelCase). In that case: 'QuestionActivity', 'UsernameStore'.

CommonsWare Over a year ago

@Arnaldo: That is a popular convention. However, AFAIK, there are no capitalization rules for Kotlin classes.

Nirwal · Accepted Answer · 2023-01-29 05:58:57Z

1

You have not created instance of class

usernameStore

import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.widget.TextView

class questionActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_question)
    var nameDisplay: TextView = findViewById(R.id.nameDisplay)
   // replace with below code
    var name2 = usernameStore().username
    nameDisplay.setText(name2)

 }
}

answered Jan 29, 2023 at 5:58

Nirwal

711 silver badge3 bronze badges

Collectives™ on Stack Overflow

Can't access variable in data class kotlin

2 Answers 2

2 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related