Flutter using Add Two Numbers | Flutter Tutorials

Add Two Numbers using Flutter

In this presentation, we'll explore how to build a simple Flutter app that can add two numbers together. We'll cover the basics of the Dart programming language, Flutter's widget system, and the steps to create a functional user interface and add the necessary logic.

main.dart:

import 'package:add_two_numbers/addtwonumbers.dart';
import 'package:flutter/material.dart';
void main() {
  runApp(const MyApp());
}
class MyApp extends StatelessWidget {
  const MyApp({super.key});
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        
        colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),
        useMaterial3: true,
      ),
      home: const AddTwoNumbers(),
    );
  }
}

addtwonumbers.dart:

import 'package:flutter/material.dart';
class AddTwoNumbers extends StatefulWidget {
  const AddTwoNumbers({super.key});
  @override
  State<AddTwoNumbers> createState() => _AddTwoNumbersState();
}
class _AddTwoNumbersState extends State<AddTwoNumbers> {
  final TextEditingController _num1Controller = TextEditingController();
  final TextEditingController _num2Controller = TextEditingController();
  final TextEditingController _resultController = TextEditingController();
  void _addNumbers(){
    setState(() {
      
      double num1 = double.tryParse(_num1Controller.text)?? 0;
      double num2 = double.tryParse(_num2Controller.text)?? 0;
      double result = num1 + num2;
      _resultController.text = result.toString();
 
    });
  }


  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text("LogicLab Academy"),
        centerTitle: true,
        backgroundColor: Colors.red,
      ),
      body: SafeArea(child: Container(
        padding:EdgeInsets.symmetric(horizontal: 15, vertical: 20),
        child: Column(
          children: [
            Text("Add Two Numbers",style: TextStyle(fontSize: 30,color: Colors.blue),),
            SizedBox(height: 15,),
            TextField(
              controller: _num1Controller,
              decoration: InputDecoration(
                labelText: "First Number",
                labelStyle: TextStyle(fontSize: 15,color: Colors.grey.shade400),
                border: OutlineInputBorder(borderRadius: BorderRadius.circular(10))
              ),
            ),
            SizedBox(height: 15,),
            TextField(
              controller: _num2Controller,
              decoration: InputDecoration(
                labelText: "Second Number",
                labelStyle: TextStyle(fontSize: 15,color: Colors.grey.shade400),
                border: OutlineInputBorder(borderRadius: BorderRadius.circular(10))
              ),
            ),
            SizedBox(height: 15,),

            ElevatedButton(
              
              style: ButtonStyle(
                padding: WidgetStatePropertyAll(EdgeInsets.only(
                  left: 150,
                  right: 150,
                  top: 10,
                  bottom: 10,
                )),
                backgroundColor: WidgetStatePropertyAll(Colors.red),
                foregroundColor: WidgetStatePropertyAll(Colors.white),
                textStyle: WidgetStatePropertyAll(TextStyle(fontSize: 20 ))
              ),
              onPressed: _addNumbers, 
              child: Text("ADD")
              ),
              SizedBox(height: 15,),
            TextField(
              controller: _resultController,
              decoration: InputDecoration(
                labelText: "Result",
                labelStyle: TextStyle(fontSize: 15,color: Colors.grey.shade400),
                border: OutlineInputBorder(borderRadius: BorderRadius.circular(10))
              ),
            ),
          ],
        ),
      )),
    );
  }
}

Implementing the Add Function:

Declare Variables

Define integer variables to store the two input numbers.

Get User Input

Retrieve the values entered by the user into the text fields.

Perform Adiition

Write the logic to add the two numbers and store the result.

Display Result

Update the UI to show the calculated sum to the user.

How to get relation value in index in yii2 and Filter

How to get relation value in index in yii2

Certainly! When using Yii2, the convention is to create a separate search model for handling search and filtering logic. Here's a basic example of a PostSearch model with filtering capabilities for the author.name attribute:

Assuming you have a Post model with a hasOne relation to Author:

1. Create a PostSearch model:

// models/PostSearch.php

namespace app\models;

use yii\base\Model;

use yii\data\ActiveDataProvider;

class PostSearch extends Post

{

    public $authorName;

    public function rules()

    {

        return [

            [['id', 'author_id'], 'integer'],

            [['title', 'content', 'authorName'], 'safe'],

        ];

    }

    public function search($params)

    {

        $query = Post::find()->joinWith('author');

        $dataProvider = new ActiveDataProvider([

            'query' => $query,

            'sort' => [

                'attributes' => [

                    'id',

                    'title',

                    'content',

                    'authorName' => [

                        'asc' => ['author.name' => SORT_ASC],

                        'desc' => ['author.name' => SORT_DESC],

                    ],

                ],

            ],

        ]);

        $dataProvider->sort->attributes['authorName'] = [

            'asc' => ['author.name' => SORT_ASC],

            'desc' => ['author.name' => SORT_DESC],

        ];

        $this->load($params);

        if (!$this->validate()) {

            return $dataProvider;

        }

        $query->andFilterWhere(['like', 'author.name', $this->authorName]);

        // Your other filtering logic goes here

        return $dataProvider;

    }

}

In your views/post/index.php, you can now use the GridView widget with the search model:

// views/post/index.php

use yii\grid\GridView;

// Other view code

<?= GridView::widget([

    'dataProvider' => $dataProvider,

    'filterModel' => $searchModel,

    'columns' => [

        // Your other columns

        [

            'attribute'=>'authorName'

            'value'=> 'author.name',

            'label' => 'Author Name',

        ],

        // Other columns

    ],

]); ?>

1. In your Post model, ensure you have defined the relation to Author:

// models/Post.php

namespace app\models;

use yii\db\ActiveRecord;

class Post extends ActiveRecord

{

    // Your other attributes and methods here

    // Define the relation to Author

    public function getAuthor()

    {

        return $this->hasOne(Author::class, ['id' => 'author_id']);

    }

}

In your PostController, use the PostSearch model in the actionIndex method:

// controllers/PostController.php

namespace app\controllers;

use Yii;

use yii\web\Controller;

use app\models\PostSearch;

class PostController extends Controller

{

    public function actionIndex()

    {

        $searchModel = new PostSearch();

        $dataProvider = $searchModel->search(Yii::$app->request->queryParams);

        return $this->render('index', [

            'searchModel' => $searchModel,

            'dataProvider' => $dataProvider,

        ]);

    }

}

 

Yii2 Gridview Dataprovider create with relationship

 

In Yii2, if you want to create a GridView with a DataProvider that includes related models and additional select columns, you can do the following:

1. Create a Query with Related Models and Additional Select Columns:

$query = YourModel::find()

    ->select(['your_table.*', 'related_table.column AS alias'])

    ->joinWith('relatedRelation')

    ->where(['your_condition'])

    ->asArray();

Create a DataProvider using the Query:

$dataProvider = new \yii\data\ActiveDataProvider([

    'query' => $query,

    'pagination' => [

        'pageSize' => 20, // Set your desired page size

    ],

]);

Configure GridView to use the DataProvider:

<?= \yii\grid\GridView::widget([

    'dataProvider' => $dataProvider,

    'columns' => [

        'attribute1',

        'attribute2',

        // ... other attributes from your model ...

        'alias', // Access the added select column

        [

            'class' => 'yii\grid\ActionColumn',

            // ... configure action buttons ...

        ],

    ],

]); ?>

Make sure to replace 'your_table', 'related_table', 'alias', 'relatedRelation', and 'attribute1', 'attribute2' with actual table and attribute names from your application.

Keep in mind that this assumes you have properly set up your models, relations, and database tables in Yii2.

Remember to adjust the column names, relations, and conditions to match your specific application. This code serves as a template and may need to be customized based on your specific requirements.

Number System Conversion

Decimal to Binary

 Decimal to Octal

Decimal to Hexadecimal

Binary to Decimal

Binary Fraction to Decimal

Octal to Decimal

Octal Fraction to Decimal

Binary to Octal

Binary Fraction to Octal

Octal to Binary

Octal Fraction to Binary

Binary to Hexadecimal

Binary Fraction to Hexadecimal

Hexadecimal to Binary

How to Swap Two Arrays In C Language

 

#include<stdio.h>

void main()

{

  int a[5] = {5,6,7,8,9};

  int b[5] = {1,2,3,4,5};

  

  int i,swap;

  for(i=0;i<5;i++)

  {

    swap = a[i];

    a[i] = b[i];

    b[i] = swap;

  } 

  printf("A = ");

  for(i=0;i<5;i++)

    printf("%d ",a[i]);

  printf("\nB = ");

  for(i=0;i<5;i++)

    printf("%d ",b[i]); 

  printf("\n");

}

Largest of three numbers in C

 #include <stdio.h>

int main()

{

 int x,y,z;

 clrscr();

 printf("Enter three numbers :");

 scanf("%d,%d,%d",&x,&y,&z);

 if(x>y)

 {

   if(x>z)

     printf("Largest value : %d ",x);

   else

     printf("Largest value : %d ",z);

 }

 else

 {

   if(y>z)

     printf("Largest value : %d",y);

   else

     printf("Largest value : %d",z);

 }

 getch();

}

C language MCQ (Multiple Choise Questions)

Art of C Programming

1 . Address stored in the pointer variable is of type __________

 Character

 Array

 Integer

 Floating

 

2. "*" is called as ___________

 Address Operator

 Scope Resolution Operator

 Value at Operator

 None of these

3. Comment on the following pointer declaration?

     int *ptr, p;

 ptr is a pointer to integer, p is not.

 ptr and p, both are pointers to integer.

 ptr is pointer to integer, p may or may not be.

 ptr and p both are not pointers to integer.

4. Which of the following are correct syntaxes to send an array as a parameter to function

 func(&array);

 func(**array);

 func(*array);

 func(array[size]);

5. Which of the following is not possible in C?

 Array of function pointer

 Returning a function pointer

 Comparison of function pointer

 None of the mentioned

 

Answers

1. Integer

2.  Value at Operator

3. ptr is a pointer to integer, p is not.

4. func(&array);

5. None of the mentioned