Android / Kotlin -Adding Two Numbers using EditText

[@VladVoytenko]

Note: @6:25 time : You need to use findViewById() to access the button ID from resource file @7:03 time : You need to use findViewById() to access the textResult ID, editNum1, editNum2 from resource file

[@monsterscaveff7634]

from where?

[@VladVoytenko]

@@monsterscaveff7634 at time frames: 6:25, 7:03

[@subhadeepmukherjee3527]

@Vlad Voytenko Sir, will you make a video on how to check odd even number in kotlin? or can you give me the java/kotlin code for the main activity?Please

[@supxjavi2831]

I am trying to make a small profit calculator using this video as an idea. What would I do for the code if I wanted to subtract editNum2 from editNum1 (Sold Price-Item Cost = Profit)

[@mohammedelaminetellai7569]

thank you but I have a problem button it's not identified in kt file

[@VladVoytenko]

check my comments under the video - it may help

[@anurajms]

thank you this was the most helpful video .

[@michaelodemena6256]

as always man a great help has a question though what if I wanted to add decimals together doesn't seem to work as it so just wanted to know what i have to change

[@VladVoytenko]

Just instead of Number widget drag and drop Number (Decimal) to your xml.... After that, chamge Kotlin addition operation from int to double. Hope it helps!

[@Music-lv8xf]

how to add two edittext number in textchanged listener?

[@VladVoytenko]

A bit old, but using Kotlin Android extensions you can do something like that: editTextRequest.textChangedListener { afterTextChanged { // Do something here... } }

[@muteiPod303]

Thank you for the helpful video

[@VladVoytenko]

You're welcome!

[@H.HamzahMD]

but its crash when no input. how to solve it please. i have try make if (input == null) , but it say null is always false

[@VladVoytenko]

you have to check editNum1 and editNum2 before calculation

[@AmitKumar-lj4dm]

@@VladVoytenko please make another video of that

[@raymundoortiz7269]

you can use Elvis Operator or something like this: val b: String? = "Kotlin" if (b != null && b.length > 0) { print("String of length ${b.length}") } else { print("Empty string") }

[@paryliak]

I am adding the solution that worked for me just in case if anyone else faces the same problem: class MainActivity : AppCompatActivity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_main) button.setOnClickListener { if (editNum1.length() > 0 && editNum2.length() > 0) { textResult.text = "Result: " + (editNum1.text.toString().toInt() + editNum2.text.toString().toInt()).toString() Toast.makeText(this, textResult.text, Toast.LENGTH_LONG).show() } else { Toast.makeText(this, "Fill in numbers", Toast.LENGTH_LONG).show() } } } }

[@subhadeepmukherjee3527]

@@VladVoytenko Sir, will you make a video on how to check odd even number in kotlin? or can you give me the java/kotlin code for the main activity?Please

[@reevechaitanya1693]

Thanks man

[@AyanKhan-it4nl]

Thanks a lot bro...

[@ricardolopez6194]

ありがとう

[@i2911]

ありがとう = Arigatau = Thank you

[@windschiefhopkins5839]

Hi, thanks I just started to learn and this is helpfull! now I am dividing, how would I round the result off to two decimals (dollars.cents) ? I have result.text = number1.text.toString().toDouble() / number2.text.toString().toDouble() cheers

[@VladVoytenko]

hey, you may use some just Kotlin instrctions to round the number. F.e,. val random = 8435.21057752090819915 val df = DecimalFormat("#.##") df.roundingMode = RoundingMode.DOWN val roundoff = df.format(random) println(roundoff) // 8435.21

[@windschiefhopkins5839]

@@VladVoytenko hm, doesnt seem to work. I just don't know enough to get ahead - probably need in-person schooling lol , so how to round my result.text which is defined in MainAcitivity.kt and printed in a TextView area in activity_main.xml sorry, don't need to answer, obviously I am lacking some basics....