Flutter get index of item in list
WebAug 25, 2024 · 1 Answer. There is no such easy way to do this, but you can use VisibilityDetector from visibility_detector package: You can get the index of the last list item that is completely visible on screen by wrapping each list item with a VisibilityDetector. itemBuilder: (context, index) { return VisibilityDetector ( key: Key (index.toString ...
Flutter get index of item in list
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WebAug 1, 2024 · If not found, index = -1 final index = people.indexWhere((element) => element.name == personName); if (index >= 0) { print('Using indexWhere: … WebAug 23, 2024 · For the index you could use indexOf(value) function from the list to get index value. For example: List list = List.generate(3, (int index) => index * index); // [0, 1, 4] list.indexOf(4) // returns 2 As for your other issue, I'd need to see more code to see how you populate myList. I would suggest this approach (if it fits) to render your Row ...
WebApr 22, 2024 · var lst = ["element1" , "element2" , "element3"]; lst.last // -> element3. The best one is lst [lst.length-1] way because in the "last" property ,it loops through the list until the last element is got , so it will be slower way. @AvisekSSarma It depends on the collection type and implementation. WebAug 12, 2024 · Iam creating a quiz App in flutter , to find whether the currect answer is selected i want to get the index number of the selected button, i doesnt know whether it is a correct approach to check the correct answer.Please help me how to get the index number when user presses the answer.
WebFeb 15, 2024 · /// The first index of [element] in this list. /// /// Searches the list from index [start] to the end of the list. /// The first time an object `o` is encountered so that `o == element`, /// the index of `o` is returned. Pay special attention to the o == element meaning that the item that you're trying to find has to implement the == operator. WebSep 20, 2024 · We can use indexOf, or indexWhere. Both return the first index of first element in the list. On the contrary, lastIndexOf and lastIndexWhere return the index of the last element. Suppose we want to implement the above Dart code in a Flutter app where we want to select an index of the List and display the associated value in bold.
WebSep 20, 2024 · We can use indexOf, or indexWhere. Both return the first index of first element in the list. On the contrary, lastIndexOf and lastIndexWhere return the index of …
WebYou would want to build your list of ListTile s within a ListView, and use List.generate constructor to get the index of the children here is a simple example: import "package:flutter/material.dart"; class ListTest extends … cummings developmentWebMay 13, 2024 · e.key will give the index e.vaule will give the value at that index. list.asMap ().entries.map ( (e) { // e.key will give you the index print (e.key.toString ()); // e.value will give you the value at that index print (e.value.toString ()); }); For anyone who wants to use mapIndexed and your IDE doesn't want to auto import the required package ... east west emerald cut ringWebApr 6, 2024 · 3. First lets fix your itemBuilder in your ListView so it indexes each element and then add that index into your showResults () function call so you have access to it: ListView.builder ( physics: … cummings development and designWebAug 1, 2024 · In this post, we will learn how to find an item in a list in Dart/Flutter through an interesting example. Suppose we have a class Person with name and age. We need to find in a provided list the person by his name. Here is the Person class: east west engineering mumbaiWebMar 11, 2024 · This is the structure of the normal Items on the List and every object contain a list of items: class RestaurantFoodList { final String id ; final String title; List items ; final String imageUrl; RestaurantFoodList({this.id,this.title,this.items,this.imageUrl}); } cummings development corpWebMar 25, 2024 · 3. Ok so for starters, lets address this: final List _categories = allCategories; List get allCategory => _categories; This is not doing anything of value. You're declaring a private variable and initializing it to a top level global variable. Then using a public getter to access a private variable that again, is ... cummings dmvWebFeb 9, 2024 · 0. Hello I am not sure that I am giving the best answer, but here are some options: Please try titleItem [0] Use one of the following : .key, .value, .first. Share. cummings declines trumps offer