Flutter 为什么我不能在控制台上打印对象中的信息
为什么我不能在dart中打印以下语句:Flutter 为什么我不能在控制台上打印对象中的信息,flutter,dart,Flutter,Dart,为什么我不能在dart中打印以下语句: print(questionBank[1].questionAnswer); print(questionBank.length); ===================================================== class Question { String questionText; bool questionAnswer; Question({String ques, bool ans}) { qu
print(questionBank[1].questionAnswer);
print(questionBank.length);
=====================================================
class Question {
String questionText;
bool questionAnswer;
Question({String ques, bool ans}) {
questionText = ques;
questionAnswer = ans;
}
}
void main{
List<Question> questionBank = [
Question(
ques: 'You can lead a cow down stairs but not up stairs.', ans: false),
Question(
ques: 'Approximately one quarter of human bones are in the feet.',
ans: true),
Question(ques: 'A slug\'s blood is green.', ans: true),
];
print(questionBank[1].questionAnswer);
print(questionBank.length);
}
课堂提问{
字符串文本;
布尔问题答案;
问题({String ques,bool ans}){
问题文本=问题;
问题答案=ans;
}
}
真空总管{
列表问题库=[
问题:(
提问:“你可以带一头牛下楼,但不能上楼。”,回答:错),
问题:(
问题:“大约四分之一的人类骨骼在脚上。”,
答:是的,
问题(提问:“鼻涕虫的血是绿色的”,回答:是的,
];
打印(问题库[1]。问题答案);
打印(问题库长度);
}
这是您的模型插入到字符串方法,通过右键单击您的模型>genrate>toString()'(Android studio)
class Question {
String questionText;
bool questionAnswer;
Question({String ques, bool ans}) {
questionText = ques;
questionAnswer = ans;
}
@override
String toString() {
return 'Question{questionText: $questionText, questionAnswer: $questionAnswer}';
}
}
然后使用like:
debugPrint(questionBank[1].questionAnswer.toString());
这是您的模型插入到字符串方法,通过右键单击您的模型>genrate>toString()'(Android studio)
class Question {
String questionText;
bool questionAnswer;
Question({String ques, bool ans}) {
questionText = ques;
questionAnswer = ans;
}
@override
String toString() {
return 'Question{questionText: $questionText, questionAnswer: $questionAnswer}';
}
}
然后使用like:
debugPrint(questionBank[1].questionAnswer.toString());
您只需重写方法
toString
,如下所示:
@override
String toString() => 'Question{questionText: $questionText, questionAnswer: $questionAnswer}';
然后你可以做:
print(yourObject);
您只需重写方法
toString
,如下所示:
@override
String toString() => 'Question{questionText: $questionText, questionAnswer: $questionAnswer}';
然后你可以做:
print(yourObject);