Kalkulator Sederhana

Membuat Projek

Projek dibuat dengan memilih New Project dan menggunakan Empty Activities, beri nama projek sesuai selera, saya sendiri menggunakan nama MyCalculator dengan minimum SDK API 26 Oreo. Setelah itu klik Finish.

 Menyusun Sumber Kode

Aplikasi ini sangat sederhana, hanya cukup mengikuti beberapa langkah berikut:

1. Buat variable num1 dan num2 untuk menyimpan nilai input dari user, jangan lupa untuk menambahkan import runtime.*

   	...
   	import androidx.compose.runtime.*
   	...
   	var num1 by remember {
   	mutableStateOf(value = "0")
   	}
   	var num2 by remember {
   	mutableStateOf(value = "0")
   	}
   	...

   view raw MainActivity.kt hosted with ❤ by GitHub
2. Membuat TextField untuk menerima input dari user dengan mensingkronisasi variabel num1 dan num2

   	...
   	TextField(value = num1, onValueChange = {
   	num1 = it
   	})
   	TextField(value = num2, onValueChange = {
   	num2 = it
   	})
   	...

   view raw MainActivity.kt hosted with ❤ by GitHub
3. Membentuk operasi perhitungan dengan button dimana pada button menggunakan aktivitas perhitungan apabila diklik. input yang berupa string akan diubah menjadi integer dan dilakukan perhitungan yang sesuai. Hasil perhitungan akan ditampilkan sebagai pop up, hal ini dilakukan dengan Toast. 

   	...
   	Button(onClick = {
   	var result = num1.toInt() + num2.toInt()
   	Toast.makeText(applicationContext, "Result is $result", Toast.LENGTH_SHORT).show()
   	}) {
   	Text(text = "Add")
   	}
   	Spacer(modifier = Modifier.width(16.dp))
   	Button(onClick = {
   	var result = num1.toInt() - num2.toInt()
   	Toast.makeText(applicationContext, "Result is $result", Toast.LENGTH_SHORT).show()
   	}) {
   	Text(text = "Sub")
   	}
   	Spacer(modifier = Modifier.width(16.dp))
   	Button(onClick = {
   	var result = num1.toInt() * num2.toInt()
   	Toast.makeText(applicationContext, "Result is $result", Toast.LENGTH_SHORT).show()
   	}) {
   	Text(text = "Mul")
   	}
   	Spacer(modifier = Modifier.width(16.dp))
   	Button(onClick = {
   	var result = num1.toInt() / num2.toInt()
   	Toast.makeText(applicationContext, "Result is $result", Toast.LENGTH_SHORT).show()
   	}) {
   	Text(text = "Div")
   	}
   	...

   view raw MainActivity.kt hosted with ❤ by GitHub

Hasil Akhir

Referensi: Referensi YT

Sumber kode lengkap sebagai berikut:

	package com.example.mycalculator
	import android.os.Bundle
	import android.widget.Toast
	import androidx.activity.ComponentActivity
	import androidx.activity.compose.setContent
	import androidx.compose.foundation.layout.Column
	import androidx.compose.foundation.layout.Row
	import androidx.compose.foundation.layout.Spacer
	import androidx.compose.foundation.layout.fillMaxSize
	import androidx.compose.foundation.layout.height
	import androidx.compose.foundation.layout.width
	import androidx.compose.material3.Button
	import androidx.compose.material3.MaterialTheme
	import androidx.compose.material3.Surface
	import androidx.compose.material3.Text
	import androidx.compose.material3.TextField
	import androidx.compose.runtime.Composable
	import androidx.compose.ui.Modifier
	import androidx.compose.ui.tooling.preview.Preview
	import com.example.mycalculator.ui.theme.MyCalculatorTheme
	import androidx.compose.runtime.*
	import androidx.compose.ui.unit.dp
	class MainActivity : ComponentActivity() {
	override fun onCreate(savedInstanceState: Bundle?) {
	super.onCreate(savedInstanceState)
	setContent {
	var num1 by remember {
	mutableStateOf(value = "0")
	}
	var num2 by remember {
	mutableStateOf(value = "0")
	}
	Column {
	TextField(value = num1, onValueChange = {
	num1 = it
	})
	TextField(value = num2, onValueChange = {
	num2 = it
	})
	Spacer(modifier = Modifier.height(32.dp))
	Row {
	Button(onClick = {
	var result = num1.toInt() + num2.toInt()
	Toast.makeText(applicationContext, "Result is $result", Toast.LENGTH_SHORT).show()
	}) {
	Text(text = "Add")
	}
	Spacer(modifier = Modifier.width(16.dp))
	Button(onClick = {
	var result = num1.toInt() - num2.toInt()
	Toast.makeText(applicationContext, "Result is $result", Toast.LENGTH_SHORT).show()
	}) {
	Text(text = "Sub")
	}
	Spacer(modifier = Modifier.width(16.dp))
	Button(onClick = {
	var result = num1.toInt() * num2.toInt()
	Toast.makeText(applicationContext, "Result is $result", Toast.LENGTH_SHORT).show()
	}) {
	Text(text = "Mul")
	}
	Spacer(modifier = Modifier.width(16.dp))
	Button(onClick = {
	var result = num1.toInt() / num2.toInt()
	Toast.makeText(applicationContext, "Result is $result", Toast.LENGTH_SHORT).show()
	}) {
	Text(text = "Div")
	}
	}
	}
	}
	}
	}

view raw MainActivity.kt hosted with ❤ by GitHub