Dart/Flutter: How to print something into the console from constructor

I want to print something to the console from my constructor as shown in the snippet below, but I get the error <blockquote> <pre><code>Context: 'Seitenzahlenrechn...

Colon after Constructor in dart

This code is from flutter gallery and i'm trying to understanding and adapting it. I would know what this syntax means: <pre><code>class DemoItem&lt;T&gt; { Dem...

Flutter null safety constructor

I am using flutter's latest(null safety) version and I created a constructor. This code does not show anything on the screen. Why can't I see icons and text?</p...

Default values of an optional parameter must be constant flutter / dart

I'm trying to organize some Site class data in an Event class, but I'm getting a "The default value of an optional parameter must be constant" and I've been struggling...

Flutter &amp; Dart, Constructor before the properties

I was watching a course and the instructor always write the constructor first, then the properties, in java, c# and other OOP languages the properties are written firs...

constructor doesnt work properly on flutter

I have create a class called Size <ul> <li>Class name: Size</li> </ul> enter code <pre><code>import 'package:flutter/material.dart'; import 'package:firstap...

Too many positional arguments: 0 expected, but 6 found flutter

I am having a <code>user model class</code> that looks like this below <pre><code>class User { String? email; String? about; String? name; String? picture;...

The constructor being called isnt a const constructor. Try removing const from the constructor invocation. Flutter How to solve?

I'm getting this error when I tried to build Object using Freezzed Package in Flutter <a href="https://i.stack.imgur.com/FeTbS.png" rel="nofollow noreferrer"><img src=...

Flutter: create const color from hex string

I am using Firebase remote config to store my color values. This gives me the flexibilty to update colors without the need to update my app. Now I have written myself...

How can a property take the default values defined in the constructor? I am using the factory method fromJson()

I have a class with non-nullable values whose default values I have defined in the constructor. <pre><code>class AirConPreferences { bool allowOn; int lowerTem...

Pass Freezed Constructor Tear-Off to Generic Widget

What the title says. I have a freezed constructor tear-off that I'm trying to pass to a Widget and it's not returning null, and I'm trying to figure out what I'm doing...

Dart: Object is giving output only once even when called multiple times

Hi I am trying to print value of 'a' property of x object but I only get output once. <pre><code>void main() { var x = Test(Boy); x; x; x; x;...

Dart(/Flutter): Create function in initializer list

I am implementing a class with multiple constructors, which is internally build around a IndexedWidgetBuilder (a function object) <pre><code>typedef IndexedWidget...

Flutter VoidCallback field default value in Constructor

This should be an easy answer but I do not find the solution yet on the internet. Let say I have 1 <code>VoidCallback</code> field name <code>onStart</code> in...

A file cant be part of more than one library. Try moving the shared declarations into the libraries, or into a new library

i have this problem while running the app, which give A file can't be part of more than one library. <pre><code>import 'package:dio/dio.dart'; import 'package:fir...