Function 获得';脚本错误';可以';我不知道为什么
我正在DartPad中练习一些问题,但无法得到解决方案,下面的代码我认为是可以的,但我在控制台中遇到了“脚本错误” 我要解决的问题是,我需要做一个有两个参数的函数,第一个参数在某个随机句子中,第二个参数是任意字符,我需要找出那个句子中有多少个字符 请回答我没有看到的错误,或者只是给我解决方案。泰Function 获得';脚本错误';可以';我不知道为什么,function,loops,flutter,for-loop,dart,Function,Loops,Flutter,For Loop,Dart,我正在DartPad中练习一些问题,但无法得到解决方案,下面的代码我认为是可以的,但我在控制台中遇到了“脚本错误” 我要解决的问题是,我需要做一个有两个参数的函数,第一个参数在某个随机句子中,第二个参数是任意字符,我需要找出那个句子中有多少个字符 请回答我没有看到的错误,或者只是给我解决方案。泰 void main() { numberOfSameCharacters(randomString: 'Today is a nice day.', character: 'a'); } void
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);
}
void main(){
numberOfSameCharacters(随机字符串:“今天是美好的一天”,字符:“a”);
}
void numberOfSameCharacters({String randomString,String character}){
int sameCharacters=0;
List randomStringList=randomString.split(“”);
对于(inti=0;i我想我可以给你一个想法
错误在这一行:
for (int i = 0; i <= randomStringList.length; i++)
希望这能解决你的问题!我想我能给你一个主意
错误在这一行:
for (int i = 0; i <= randomStringList.length; i++)
希望这能解决您的问题!我也有同样的问题,请查看:
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(
'$_counter',
style: Theme.of(context).textTheme.headline4,
),
Text(
'ui',
style: Theme.of(context).textTheme.headline5,
),
Slider(
min: 0,
max: 2,
value: _value,
onChanged: (value) {
setState(() {
_value = value;
});
},
),
],
),
),
floatingActionButton: FloatingActionButton(
onPressed: _incrementCounter,
tooltip: 'Increment',
child: Icon(Icons.add),
),
);
}
}
导入“包装:颤振/材料.省道”;
var-epicMap={'Key1':345'key2':'map-example'};
void main()=>runApp(MyApp());
类MyApp扩展了无状态小部件{
@凌驾
小部件构建(构建上下文){
返回材料PP(
标题:“颤振演示”,
debugShowCheckedModeBanner:false,
主题:主题数据(
主样本:颜色。蓝色,
),
主页:MyHomePage(标题:“使用颤振和飞镖进行映射”),
);
}
}
类MyHomePage扩展StatefulWidget{
最后的字符串标题;
MyHomePage({Key?Key,必选this.title}):super(Key:Key);
@凌驾
_MyHomePageState createState()=>\u MyHomePageState();
}
类_MyHomePageState扩展状态{
int _计数器=0;
get key2=>null;
void _incrementCounter(){
设置状态(){
_计数器++;
});
}
@凌驾
小部件构建(构建上下文){
var_值;
返回脚手架(
appBar:appBar(
标题:文本(widget.title),
),
正文:中(
子:列(
mainAxisAlignment:mainAxisAlignment.center,
儿童:[
正文(
“映射输出:”,
),
正文(
“$”计数器“,
风格:Theme.of(context).textTheme.headline4,
),
正文(
“ui”,
风格:Theme.of(context).textTheme.headline5,
),
滑块(
分:0,,
最高:2,
值:_值,
一旦更改:(值){
设置状态(){
_价值=价值;
});
},
),
],
),
),
浮动操作按钮:浮动操作按钮(
按下时:\ u递增计数器,
工具提示:“增量”,
子:图标(Icons.add),
),
);
}
}
我也有同样的问题,请检查以下内容:
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(
'$_counter',
style: Theme.of(context).textTheme.headline4,
),
Text(
'ui',
style: Theme.of(context).textTheme.headline5,
),
Slider(
min: 0,
max: 2,
value: _value,
onChanged: (value) {
setState(() {
_value = value;
});
},
),
],
),
),
floatingActionButton: FloatingActionButton(
onPressed: _incrementCounter,
tooltip: 'Increment',
child: Icon(Icons.add),
),
);
}
}
导入“包装:颤振/材料.省道”;
var-epicMap={'Key1':345'key2':'map-example'};
void main()=>runApp(MyApp());
类MyApp扩展了无状态小部件{
@凌驾
小部件构建(构建上下文){
返回材料PP(
标题:“颤振演示”,
debugShowCheckedModeBanner:false,
主题:主题数据(
主样本:颜色。蓝色,
),
主页:MyHomePage(标题:“使用颤振和飞镖进行映射”),
);
}
}
类MyHomePage扩展StatefulWidget{
最后的字符串标题;
MyHomePage({Key?Key,必选this.title}):super(Key:Key);
@凌驾
_MyHomePageState createState()=>\u MyHomePageState();
}
类_MyHomePageState扩展状态{
int _计数器=0;
get key2=>null;
void _incrementCounter(){
设置状态(){
_计数器++;
});
}
@凌驾
小部件构建(构建上下文){
var_值;
返回脚手架(
appBar:appBar(
标题:文本(widget.title),
),
正文:中(
子:列(
mainAxisAlignment:mainAxisAlignment.center,
儿童:[
正文(
“映射输出:”,
),
正文(
“$”计数器“,
风格:Theme.of(context).textTheme.headline4,
),
正文(
“ui”,
风格:Theme.of(context).textTheme.headline5,
),
滑块(
分:0,,
最高:2,
值:_值,
一旦更改:(值){
设置状态(){
_价值=价值;
});
},
),
],
),
),
浮动操作按钮:浮动操作按钮(
按下时:\ u递增计数器,
工具提示:“增量”,
子:图标(Icons.add),
),
);
}
}
可能会多解释一点问题,控制台中有什么?哪行代码?可能会多解释一点问题,控制台中有什么?哪行代码?