Convert bool into a int to display number in Flutter widget

user_14663325 0
Viewed 189

I have a chats class:

List<Message> chats = [
  Message(
    sender: roberta,
    time: '5:30 PM',
    text: 'Hey, how\'s it going? What did you do today?',
    isLiked: false,
    unread: true,
  ),
  Message(
    sender: roberta,
    time: '5:30 PM',
    text: 'Hey, how\'s it going? What did you do today?',
    isLiked: false,
    unread: true,
  ),
  Message(
    sender: stefano,
    time: '4:30 PM',
    text: 'Hey, how\'s it going? What did you do today?',
    isLiked: false,
    unread: true,
  ),

With messages property and one of them is "unread" property. How I can assign true to an Int like a number 1 and if is false is 0 I need to take this bool "unread" and transform into a number to show how many unreads message into a notification widget in flutter

Any input?

flutter
2 Answers

I think this is what you need.

    List<Messages> x = [
    Messages("asdg", true),
    Messages("dagd", false),
    Messages("asdg", true)
  ];
  print(x
      .map<int>((element) => element.read ? 1 : 0)
      .fold<int>(0, (previous, obj) => previous + obj));

For efficiency purposes though, if this is a chat app. You should be subscribed to some kind of Stream and only save a counter which you increment if there onChanged is triggered by your listener.

user_113203450

Try This

class Message {
  String sender;
  String   time;
  String   text;
  bool  isLiked;
  bool  unread;
  
   Message({this.sender= "",
              this.time = "",
              this.text= "",
              this.isLiked= false,
              this.unread= false });
}

void main() {
  
  List<Message> chats = [
  Message(
    sender: "roberta",
    time: '5:30 PM',
    text: 'Hey, how\'s it going? What did you do today?',
    isLiked: false,
    unread: true,
  ),
  Message(
    sender: "roberta",
    time: '5:30 PM',
    text: 'Hey, how\'s it going? What did you do today?',
    isLiked: false,
    unread: true,
  ),
  Message(
    sender: "stefano",
    time: '4:30 PM',
    text: 'Hey, how\'s it going? What did you do today?',
    isLiked: false,
    unread: true,
  )
    ];
  
  int unreadCount=0;
  
  for (int i = 0; i < chats.length; i++) {
    if(chats[i].unread)
      unreadCount++;
  }
  
  print(" Total Unread messages :"+ unreadCount.toString());
}

OR use folds like this

 int cnt=0;
  chats.fold(0, (t, e) => (e.unread?cnt++:0)); 
  
  print(" Total Unread messages :"+ cnt.toString());
user_18349410
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