1. Settings

I want to make a BMI calculator. I set my calculator to distinguish five different states of human body (high fast, fast, chubby, normal, thin). I put those states on the list. However, If I call one of those states using 'num[0]', it doesn't work properly.

2. What I made

3. What I want to know

Instead of facing the real 'num[0]', I want this app to embed the first data inside the list 'num'.

4. My WHOLE code

import 'package:flutter/material.dart';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: const MyHomePage(),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({Key? key}) : super(key: key);

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  //1. variables

  late TextEditingController input1;
  late TextEditingController input2;
  late double sum;
  late String sentence;
  var num = ['hight fast', 'fast', 'chubby', 'normal', 'thin'];

  //2. initialization
  @override
  void initState() {
    super.initState();

    input1 = TextEditingController();
    input2 = TextEditingController();
    sum = 0;

    sentence = "";
  }

//3. main
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('BMI CALCULATOR'),
        centerTitle: true,
        backgroundColor: Colors.amber,
      ),
      body: Center(
        child: Padding(
          padding: const EdgeInsets.all(20.0),
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: [
              TextField(
                controller: input1,
                keyboardType: TextInputType.number,
                decoration: const InputDecoration(
                    labelText: 'Enter your height (: cm)'),
              ),
              TextField(
                controller: input2,
                keyboardType: TextInputType.number,
                decoration: const InputDecoration(
                    labelText: 'Enter your weight (: kg)'),
              ),
              const SizedBox(
                height: 21,
              ),
              ElevatedButton(
                style: ElevatedButton.styleFrom(
                  primary: Colors.amber,
                ),
                onPressed: () {
                  onCheck();
                },
                child: const Text('RESULT'),
              ),
              Padding(
                padding: const EdgeInsets.all(20.0),
                child: Text(
                  sentence,
                  style: const TextStyle(
                    color: Colors.brown,
                    fontSize: 21,
                    fontWeight: FontWeight.bold,
                  ),
                ),
              ),
            ],
          ),
        ),
      ),
    );
  }

  onCheck() {
    setState(() {
      sum = double.parse(input2.text) /
          (((double.parse(input1.text)) / 100) *
              ((double.parse(input1.text)) / 100));

      if (sum >= 30) {
        sentence = 'your BMI is $sum, your state is num[0]';
      } else if (sum >= 25) {
        sentence = 'your BMI is $sum, your state is num[0]';
      } else if (sum >= 23) {
        sentence = 'your BMI is $sum, your state is num[0]';
      } else if (sum >= 18.5) {
        sentence = 'your BMI is $sum, your state is num[0]';
      } else {
        sentence = 'your BMI is $sum, your state is num[0]';
      }
    });
  }
}

Thanks for reading. I appreciate all your answers, even tiny short small ideas.

CodePudding user response：

You have to use num like this:

'Your BMI is ... ${num[0]}'

CodePudding user response：

This is the right way

sentence = 'your BMI is $sum, your state is ${num[0]}'