CODEWITHSUNDEEP
functionloopsflutterfor-loopdart
Stefan Lukovic
Stefan Lukovic

Reputation: 95

Getting 'Script error' and can't find why

I'm practicing a little bit in DartPad some problems and can't get the solution, the code below is what I think is OK, but I'm getting 'Script error' in the console.

The problem that I'm solving is that I need to make function that has two arguments, first one in some random sentence and second is any character, and I need to find how many characters are in that sentence.

Please respond with the error that I don't see or just give me solution. Ty

void main() {
  numberOfSameCharacters(randomString: 'Today is a nice day.', character: 'a');
}

void numberOfSameCharacters({String randomString, String character}) {
  int sameCharacters = 0;

  List<String> randomStringList = randomString.split('');

  for (int i = 0; i <= randomStringList.length; i++) {
    if (character.toLowerCase() == randomStringList[i].toLowerCase()) {
      sameCharacters += 1;
    }
  }

  print(sameCharacters);
}

Upvotes: 0

Views: 469

Answers (2)

user15516415
user15516415

Reputation: 11

I have the same problem, check this out :

import 'package: flutter/material.dart';

var epicMap = {'Key1': 345, 'key2': 'map example'};

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      debugShowCheckedModeBanner: false,
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(title: 'Mapping with flutter and dart'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  final String title;
  MyHomePage({Key? key, required this.title}) : super(key: key);

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  int _counter = 0;

  get key2 => null;

  void _incrementCounter() {
    setState(() {
      _counter++;
    });
  }

  @override
  Widget build(BuildContext context) {
    var _value;
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            Text(
              'Map output:',
            ),
            Text(
              '$_counter',
              style: Theme.of(context).textTheme.headline4,
            ),
            Text(
              'ui',
              style: Theme.of(context).textTheme.headline5,
            ),
            Slider(
              min: 0,
              max: 2,
              value: _value,
              onChanged: (value) {
                setState(() {
                  _value = value;
                });
              },
            ),
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _incrementCounter,
        tooltip: 'Increment',
        child: Icon(Icons.add),
      ),
    );
  }
}

Upvotes: 1

Shri Hari L
Shri Hari L

Reputation: 4894

I think I could give you an idea.

Error is in this line:

for (int i = 0; i <= randomStringList.length; i++)

As we know List / Arrays of size N has index values from 0 to N-1, but this code runs loops for 0 to N. So we get RangeError

Corrected Code:

void main() {
  numberOfSameCharacters(randomString: 'Today is a nice day.', character: 'a');
}

void numberOfSameCharacters({String randomString, String character}) {
  int sameCharacters = 0;

  List<String> randomStringList = randomString.split('');

  for (int i = 0; i < randomStringList.length; i++) {
    if (character.toLowerCase() == randomStringList[i].toLowerCase()) {
      sameCharacters += 1;
    }
  }

  print(sameCharacters);
}

Hope that solves your issue!

Upvotes: 1

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