export class MovieComponent {

  @Input() movie: Movie;

}

Error! Property movie has no initializer and is not assigned directly in the constructor.

@Input() movie: Movie | null = null;

class C {
    baz: boolean | undefined;
}

class C {
    bar = "hello";
}

class C {
    foo!: number;

    ngOnInit() {
        this.foo = 0;
    }
}

Installing And Using .NET 4.7.x, .NET Core 2.0, And C# 7.x With VS 2017 

CREATE FUNCTION dbo.checkPerson(@data XML)
RETURNS BIT WITH SCHEMABINDING AS
BEGIN
   RETURN @data.exist('/people/person')
END
GO

CREATE TABLE tblXML
(
id INT PRIMARY KEY,
doc XML CHECK(dbo.checkPerson(doc)=1)  
)
GO

 INSERT INTO tblXML (id,  doc) VALUES
(
 1, '<people><person name="Vahid"/></people>'
)

INSERT INTO tblXML (id,  doc) VALUES
(
 2, '<people><emp name="Vahid"/></people>'
)

 The INSERT statement conflicted with the CHECK constraint "CK__tblXML__doc__060DEAE8".
The conflict occurred in database "testdb", table "dbo.tblXML", column 'doc'.
The statement has been terminated.

 CREATE TABLE xml_tab
(
 id INT IDENTITY PRIMARY KEY,
 xml_col  XML
)

 INSERT INTO xml_tab
VALUES ('<people><person name="Vahid"/></people>')
INSERT INTO xml_tab
VALUES ('<people><person name="Farid"/></people>')

 CREATE FUNCTION getIdValue(@doc XML)
RETURNS int WITH SCHEMABINDING AS
BEGIN
  RETURN @doc.value('/*[1]/@Id', 'int')
END

 CREATE TABLE docs_tab
(
id INT PRIMARY KEY,
doc XML,
CONSTRAINT id_chk CHECK(dbo.getIdValue(doc)=id)  
)

 INSERT INTO docs_tab (id,  doc) VALUES
(
 1, '<Invoice Id="1"/>'
)

INSERT INTO docs_tab (id,  doc) VALUES
(
 2, '<Invoice Id="1"/>'
)

 The INSERT statement conflicted with the CHECK constraint "id_chk".
The conflict occurred in database "testdb", table "dbo.docs_tab".
The statement has been terminated.

 CREATE TABLE Invoices
(
 doc XML,
 id AS dbo.getIdValue(doc) PERSISTED PRIMARY KEY
)

 INSERT INTO Invoices VALUES
(
 '<Invoice Id="1"/>'
)
INSERT INTO Invoices VALUES
(
 '<Invoice Id="1"/>'
)

 Violation of PRIMARY KEY constraint 'PK__Invoices__3213E83F145C0A3F'.
Cannot insert duplicate key in object 'dbo.Invoices'. The duplicate key value is (1).
The statement has been terminated.

 DECLARE @doc XML
SET @doc = '<foo bar="baz" />'
SELECT @doc.query('/foo/@bar')

 XQuery [query()]: Attribute may not appear outside of an element

 DECLARE @doc XML
SET @doc = '<foo bar="baz" />'
SELECT @doc.query('data(/foo/@bar)')

 DECLARE @x XML
SET @x = '<x>hello<y>world</y></x><x>again</x>'
SELECT @x.query('data(/*)')

 DECLARE @x XML
SET @x = '<x>hello<y>world</y></x><x>again</x>'
SELECT @x.query('string(/*)')

 XQuery [query()]: 'string()' requires a singleton (or empty sequence), found operand of type 'element(*,xdt:untyped) *'

 SELECT @x.query('string(/*[1])')

 SELECT @x.query('string(/)')

 DECLARE @x XML = '<age>12</age>'
SELECT @x.query('string(/age[1])')

 CREATE XML SCHEMA COLLECTION root_el AS
'<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
                  targetNamespace="urn:geo">
      <xs:element name="Root" type="xs:string" />    
</xs:schema>
'
GO

 DECLARE @xmlDoc XML
SET @xmlDoc = '<g:Root xmlns:g="urn:geo">datadata...</g:Root>'
SELECT @xmlDoc.query('
declare namespace g="urn:geo";
/g:Root/text()
')

 DECLARE @xmlDoc XML(root_el)
SET @xmlDoc = '<g:Root xmlns:g="urn:geo">datadata...</g:Root>'
SELECT @xmlDoc.query('
declare namespace g="urn:geo";
/g:Root[1]/text()
')

 XQuery [query()]: 'text()' is not supported on simple typed or 'http://www.w3.org/2001/XMLSchema#anyType'
elements, found 'element(g{urn:geo}:Root,xs:string) *'.

 DECLARE @xmlDoc XML(root_el)
SET @xmlDoc = '<g:Root xmlns:g="urn:geo">datadata...</g:Root>'
SELECT @xmlDoc.query('
declare namespace g="urn:geo";
data(/g:Root[1])
')

data(/age/text())

> create-react-app sample-02
> cd sample-02
> npm start

./src/index.js
  Line 14:15:  'i' is not defined  no-undef

Search for the keywords to learn more about each error.

 const x = 1;
x = 2; // Attempting to override 'x' which is a constant.
 

const person = {
  name: "User 1",
  walk: function() {}, // method
  talk() {} // concise method
};

const person = {
  name: "User 1",
  walk() {},
  talk() {}
};

person.talk();
person.name = "User 3";
person["name"] = "User 2";

const targetMember = "name";
person[targetMember] = "User 2";

const person = {
  name: "User 1",
  walk() {
    console.log(this);
  },
  talk() {}
};

person.walk();

const walk = person.walk;
console.log(walk);

const walk2 = person.walk.bind(person);
console.log(walk2);
walk2();

const square = function(number) {
  return number * number;
};

const square2 = (number) => {
  return number * number;
};

const square2 = number => {
  return number * number;
};

const square3 = number => number * number;
console.log(square3(5));

var activeJobs = jobs.filter(function(job) {
  return job.isActive;
});

var activeJobs2 = jobs.filter(job => job.isActive);

const user = {
  name: "User 1",
  talk() {
    console.log(this);
  }
};
user.talk();

const user = {
  name: "User 1",
  talk() {
    setTimeout(function() {
      console.log(this);
    }, 1000);
  }
};
user.talk();

const user2 = {
  name: "User 2",
  talk() {
    var self = this;
    setTimeout(function() {
      console.log(self);
    }, 1000);
  }
};
user2.talk();

const user3 = {
  name: "User 3",
  talk() {
    setTimeout(() => console.log(this), 1000);
  }
};
user3.talk();

               case ShapeType.Ellipse:
                    if (isFill)
                        g.FillEllipse(new SolidBrush(backgroundColor), x, y, width, height);
                    //else
                    g.DrawEllipse(new Pen(foreColor, thickness), x, y, width, height);
                    break;

//--------------------------------[Change to]-------=>

               case ShapeType.Ellipse:
                    if (isFill)
                        g.FillEllipse(Brush, x, y, width, height);
                    //else
                    g.DrawEllipse(new Pen(foreColor, thickness), x, y, width, height);
                    break;

class Person {
    constructor(firstName, lastName) {
       this.firstName = firstName;
       this.lastName = lastName;
    }

    fullName() {
      return `${this.firstName} ${this.lastName}`;
    }
}

const person = new Person('Vahid', 'N');
person.firstName; // 'Vahid'
person.lastName; // 'N'
person.fullName; // function fullName() {…}

class Person {
    constructor(firstName, lastName) {
       this.firstName = firstName;
       this.lastName = lastName;
    }

    get fullName() {
      return `${this.firstName} ${this.lastName}`;
    }
}

function Person(firstName, lastName) {
   this.firstName = firstName;
   this.lastName = lastName;
}

Object.defineProperty(Person.prototype, 'fullName', {
   get: function () {
      return this.firstName + ' ' + this.lastName;
   }
});

Object.defineProperty(Person.prototype, 'fullName', {
    enumerable: false,
    writable: false,
    get: function () {
      return this.firstName + ' ' + this.lastName;
    }
});

function decoratorName(target, key, descriptor) {
 // …
}

function readonly(target, key, descriptor) {
   descriptor.writable = false;
   return descriptor;
}

class Person {
    constructor(firstName, lastName) {
       this.firstName = firstName;
       this.lastName = lastName;
    }

    @readonly get fullName() {
      return `${this.firstName} ${this.lastName}`;
    }
}

> npm install core-decorators

@autobind
@deprecate
@readonly
@memoize
@debounce
@profile

> create-react-app state-management-with-mobx-part1
> cd state-management-with-mobx-part1
> npm start

> npm install --save mobx

import { autorun, observable } from "mobx";

import React from "react";
import ReactDOM from "react-dom";

ReactDOM.render(
  <div>
    <input type="text" id="text-input" />
    <div id="text-display"></div>
    <div id="text-display-uppercase"></div>
  </div>,
  document.getElementById("root")
);

const input = document.getElementById("text-input");
const textDisplay = document.getElementById("text-display");
const loudDisplay = document.getElementById("text-display-uppercase");

console.log({ observable, autorun, input, textDisplay, loudDisplay });

{
  value: "Hello world!",
  get uppercase() {
    return this.value.toUpperCase();
  }
}

const text = observable({
  value: "Hello world!",
  get uppercase() {
    return this.value.toUpperCase();
  }
});

input.addEventListener("keyup", event => {
   text.value = event.target.value;
});

autorun(() => {
   textDisplay.textContent = text.value;
   loudDisplay.textContent = text.uppercase;
});

const onChange = (oldValue, newValue) => {
  // Tell MobX that this value has changed.
}

const observable = (value) => {
  return {
    get() { return value; },
    set(newValue) {
      onChange(this.get(), newValue);
      value = newValue;
    }
  }
}

    public static class IoC
    {  
        public static IContainer Initialize()
        {
            var container = new Container(x =>
            {

               x.For<IUnitOfWork>().HybridHttpOrThreadLocalScoped().Use(() => new baranDbContext());
                x.For<IUserService>().Use<UserService>();
                x.For<IUserMetaDataService>().Use<UserMetaDataService>();
            });

            return container;
        }
        public class StructureMapControllerFactory : DefaultControllerFactory
        {
            private readonly IContainer _container;

            public StructureMapControllerFactory(IContainer container)
            {
                _container = container;
            }
            protected override IController GetControllerInstance(RequestContext requestContext, Type controllerType)
            {
                if (controllerType == null)
                    return null;

                return (IController)_container.GetInstance(controllerType);
            }
        }
} 

var userService = ObjectFactory.GetInstance<IUserService>();

using System.IO;
using System.Xml;
using System.Xml.Serialization;

namespace DNTViewer.Common.Toolkit
{
    public static class Serializer
    {
        public static string Serialize<T>(T type)
        {
            var serializer = new XmlSerializer(type.GetType());
            using (var stream = new MemoryStream())
            {
                serializer.Serialize(stream, type);
                stream.Seek(0, SeekOrigin.Begin);
                using (var reader = new StreamReader(stream))
                {
                    return reader.ReadToEnd();
                }
            }
        }
    }
}

        private string createXmlFile(string dir)
        {
            var xLinq = new XElement("ArrayOfPost",
                        _blogPosts
                            .AsNoTracking()
                            .Include(x => x.Comments)
                            .Include(x => x.User)
                            .Include(x => x.Tags)
                            .OrderBy(x => x.Id)
                            .ToList()
                            .Select(x => new XElement("Post", postXElement(x)))
                            );

            var xmlFile = Path.Combine(dir, "dot-net-tips-database.xml");
            xLinq.Save(xmlFile);
            return xmlFile;
        }

        private static XElement[] postXElement(BlogPost x)
        {
            return new XElement[]
            {
                new XElement("Id", x.Id),
                new XElement("Title", x.Title),
                new XElement("Body", x.Body),
                new XElement("CreatedOn", x.CreatedOn),
                tagElement(x),
                new XElement("User",
                                new XElement("Id", x.UserId.Value),
                                new XElement("FriendlyName", x.User.FriendlyName))
            }.Where(item => item != null).ToArray();
        }

        private static XElement tagElement(BlogPost x)
        {
            var tags = x.Tags.Any() ?
                            x.Tags.Select(y =>
                                        new XElement("Tag",
                                                new XElement("Id", y.Id),
                                                new XElement("Name", y.Name)))
                                  .ToArray() : null;
            if (tags == null)
                return null;

            return new XElement("Tags", tags);
        }

 Get Browser Info,Os Info and Device Type

public void ConfigureServices(IServiceCollection services)
{
// Add browser detection services.
    services.AddDetection()
                 .AddDevice();
.AddBrowser()   // concept
.AddEngine()    // concept
.AddPlatform(); // concept

    // Add framework services.
    services.AddMvc();
}

public class HomeController : Controller
{    
    private readonly IUserAgent _useragent;    
    private readonly IBrowser _browser;
    private readonly IEngine _engine;
    private readonly IPlatform _platform;
private readonly IUserAgent _useragent;
    private readonly IDevice _device; 

    public HomeController(IBrowserResolver browserResolver, 
        IEngineResolver engineResolver, IDeviceResolver deviceResolver,
        IPlatformResolver platformResolver)
    {
        _useragent = browserResolver.UserAgent,        
        _browser = browserResolver.Browser,
        _engine = engineResolver.Engine,
        _platform = platformResolver.Platform
        _useragent = deviceResolver.UserAgent,
        _device = deviceResolver.Device
    }

    public IActionResult Index()
    {            
        return View();
    }
}