"dependencies": {
    // ...
    "@angular/router": "^3.0.0-alpha.7",
    // ...  
},

import { provideRouter, RouterConfig } from '@angular/router';

import { ProductListComponent } from './products/product-list.component';
import { WelcomeComponent } from './home/welcome.component';
import { ProductDetailComponent } from './products/product-detail.component';
import { ProductFormComponent }  from './products/product-form.component';
import { SignupFormComponent } from './users/signup-form.component';
import { TypedShaComponent } from './using-third-party-libraries/typed-sha.component';
import { UnTypedShaComponent } from './using-third-party-libraries/untyped-sha.component';
import { UsingJQueryAddonsComponent } from './using-jquery-addons/using-jquery-addons.component';

export const routes: RouterConfig = [
    { path: '', component: WelcomeComponent },
    { path: 'welcome', component: WelcomeComponent },
    { path: 'products', component: ProductListComponent },
    { path: 'product/:id', component: ProductDetailComponent },
    { path: 'addproduct', component: ProductFormComponent },
    { path: 'adduser', component: SignupFormComponent },
    { path: 'typedsha', component: TypedShaComponent },
    { path: 'untypedsha', component: UnTypedShaComponent },
    { path: 'usingjquery', component: UsingJQueryAddonsComponent }
];

export const APP_ROUTER_PROVIDERS = [
  provideRouter(routes)
];

 <base href=".">

 // ...
import { APP_ROUTER_PROVIDERS } from './app.routes';
// ...
bootstrap(AppComponent, [
   // ...
   APP_ROUTER_PROVIDERS
])
.catch(err => console.error(err));

 import { ROUTER_DIRECTIVES } from '@angular/router';

 <a [routerLink]="['/welcome']">Home</a>

import { Component, OnInit, OnDestroy } from '@angular/core';
import { Router, ActivatedRoute } from '@angular/router';

@Component({
    templateUrl: 'app/products/product-detail.component.html'
    //template: require('./product-detail.component.html')//for webpack
})
export class ProductDetailComponent implements OnInit, OnDestroy {
    private sub: any;
    pageTitle: string = 'Product Detail';
    constructor(private _route: ActivatedRoute, private _router: Router) {
    }

    ngOnInit(): void {
        this.sub = this._route.params
            .subscribe(params => {
                let id = +params['id']; // (+) converts string 'id' to a number
                this.pageTitle += `: ${id}`;
            });
    }

    ngOnDestroy(): void {
        this.sub.unsubscribe(); // we must unsubscribe before Angular destroys the component. Failure to do so could create a memory leak.
    }

    onBack(): void {
        this._router.navigate(['/products']);
    }
}

 <a [routerLink]="['/product', product.productId]">
  {{product.productName}}
</a>

interface Duck {
    walk: () => void;
    swim: () => void;
    quack: () => void;
}

let probablyADuck = {
    walk: () => console.log('walking like a duck'),
    swim: () => console.log('swimming like a duck'),
    quack: () => console.log('quacking like a duck')
}

function FlyOverWater(bird: Duck) { }

FlyOverWater(probablyADuck); // works!

interface Book {
    id: number;
    title: string;
    author: string;
    pages?: number;
    markDamaged: (reason: string) => void;
}

function CreateCustomerID(name: string, id: number): string {
    return name + id;
}

 let IdGenerator: (chars: string, nums: number) => string;

IdGenerator = CreateCustomerID;

interface StringGenerator {
     (chars: string, nums: number): string;
}

 let IdGenerator: StringGenerator;

interface LibraryResource {
   catalogNumber: number;
}

interface LibraryBook {
   title: string;
}

interface Encyclopedia extends LibraryResource, LibraryBook {
   volume: number;
}

let refBook: Encyclopedia = {
   catalogNumber: 1234,
   title: 'The Book of Everything',
   volume: 1
}

interface Librarian {
   doWork: () => void;
}

class ElementarySchoolLibrarian implements Librarian {
   doWork() {
     console.log('Reading to and teaching children...');
   }
}

 let kidsLibrarian: Librarian = new ElementarySchoolLibrarian();
kidsLibrarian.doWork();

var blogs = from blog in Blogs
   where blog.Name.Contains("Development")
   select blog;

var blogs = from blog in Blogs
   where blog.Name.ComputeHash() == 0
   select blog;

public class Blog
{
   public int BlogId { get; set; }
   public string Url { get; set; }  
}

    public static class StringExtensions
    {
        public static int ComputeHash(this string str)
        {
            var hash = 0;
            foreach (var ch in str)
            {
                hash += (int)ch;
            }
            return hash;
        }
    }

using (var context = new BloggingContext())
{
   var blogs = context.Blogs
     .Where(blog => blog.Url.ComputeHash() >= 10)
     .ToList();
   Console.WriteLine(blogs.First().Url);
}

SELECT [blog].[BlogId], [blog].[Url]
   FROM [Blogs] AS [blog]

var idUrls = context.Blogs
   .Select(b => new
   {
      IdUrlString = string.Join(", ", b.BlogId, b.Url),
   }).ToList();

    public class BloggingContext : DbContext
    {
        public BloggingContext()
        { }

        public BloggingContext(DbContextOptions options)
            : base(options)
        { }

        public DbSet<Blog> Blogs { get; set; }

        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        {
            if (!optionsBuilder.IsConfigured)
            {
                optionsBuilder.UseSqlServer(@"Server=(localdb)\mssqllocaldb;Database=Demo.ClientSideEvaluation;Trusted_Connection=True;");
                optionsBuilder.ConfigureWarnings(warnings =>
                {
                    warnings.Log(CoreEventId.IncludeIgnoredWarning);
                    warnings.Log(RelationalEventId.QueryClientEvaluationWarning);
                });
            }
        }
    }

 warn: Microsoft.EntityFrameworkCore.Query[200500]
The LINQ expression 'where ([blog].Url.ComputeHash() >= 10)' could not be translated and will be evaluated locally.

var idUrls2 = context.Blogs
   .Select(b => new
   {
     IdUrlString = b.BlogId + "," + b.Url
   }).ToList();

SELECT (CAST([b].[BlogId] AS nvarchar(max)) + N',') + [b].[Url] AS [IdUrlString]
FROM [Blogs] AS [b]

<!DOCTYPE html>
<html>
<head>
    <title>ASP.NET Web API</title>
    <script src="../../Scripts/jquery-1.7.2.min.js" 
        type="text/javascript"></script>
</head>
<body>
    <div>
        <h1>All Products</h1>
        <ul id='products' />
    </div>
    <div>
        <label for="prodId">ID:</label>
        <input type="text" id="prodId" size="5"/>
        <input type="button" value="Search" onclick="find();" />
        <p id="product" />
    </div>
</body>
</html>

<script type="text/javascript">
    $(document).ready(function () {
        // Send an AJAX request
        $.getJSON("api/products/",
        function (data) {
            // On success, 'data' contains a list of products.
            $.each(data, function (key, val) {

                // Format the text to display.
                var str = val.Name + ': $' + val.Price;

                // Add a list item for the product.
                $('<li/>', { html: str })    
                .appendTo($('#products'));   
            });
        });
    });
</script>

function find() {
    var id = $('#prodId').val();
    $.getJSON("api/products/" + id,
        function (data) {
            var str = data.Name + ': $' + data.Price;
            $('#product').html(str);
        })
    .fail(
        function (jqXHR, textStatus, err) {
            $('#product').html('Error: ' + err); 
        });
}

using System.Drawing;

namespace PWS.ObjectOrientedPaint.Models
{
    /// <summary>
    /// Ellipse Draw
    /// </summary>
    public class Ellipse : Shape
    {
        #region Constructors (2)

        /// <summary>
        /// Initializes a new instance of the <see cref="Ellipse" /> class.
        /// </summary>
        /// <param name="startPoint">The start point.</param>
        /// <param name="endPoint">The end point.</param>
        /// <param name="zIndex">Index of the z.</param>
        /// <param name="foreColor">Color of the fore.</param>
        /// <param name="thickness">The thickness.</param>
        /// <param name="isFill">if set to <c>true</c> [is fill].</param>
        /// <param name="backgroundColor">Color of the background.</param>
        public Ellipse(PointF startPoint, PointF endPoint, int zIndex, Color foreColor, byte thickness, bool isFill, Color backgroundColor)
            : base(startPoint, endPoint, zIndex, foreColor, thickness, isFill, backgroundColor)
        {
            ShapeType = ShapeType.Ellipse;
        }

        /// <summary>
        /// Initializes a new instance of the <see cref="Ellipse" /> class.
        /// </summary>
        public Ellipse()
        {
            ShapeType = ShapeType.Ellipse;
        }

        #endregion Constructors

        #region Methods (1)

        // Public Methods (1) 

        /// <summary>
        /// Draws the specified g.
        /// </summary>
        /// <param name="g">The g.</param>
        public override void Draw(Graphics g)
        {
            if (IsFill)
                g.FillEllipse(BackgroundBrush, StartPoint.X, StartPoint.Y, Width, Height);
            g.DrawEllipse(Pen, StartPoint.X, StartPoint.Y, Width, Height);
            base.Draw(g);
        }

        #endregion Methods
    }
}

import React, { Component } from "react";

class Form extends Component {
    state = {
        data:{},
        errors:{}
     }

import Joi from "@hapi/joi";

  doSubmit = () => {
    // call the server
    console.log("Submitted!");
  };

import Form from "./common/form";
// ...

class LoginForm extends Form {

  renderButton(label) {
    return (
      <button disabled={this.validate()} className="btn btn-primary">
        {label}
      </button>
    );
  }

{this.renderButton("Login")}

  import Input from "./input";
  //...

  renderInput(name, label) {
    const { data, errors } = this.state;
    return (
      <Input
        name={name}
        label={label}
        value={data[name]}
        onChange={this.handleChange}
        error={errors[name]}
      />
    );

  render() {
    return (
      <form onSubmit={this.handleSubmit}>
        {this.renderInput("username", "Username")}
        {this.renderInput("password", "Password")}
        {this.renderButton("Login")}
      </form>
    );
  }

  renderInput(name, label, type = "text") {
    const { data, errors } = this.state;
    return (
      <Input
        name={name}
        type={type}
        label={label}
        value={data[name]}
        onChange={this.handleChange}
        error={errors[name]}
      />
    );
  }

  render() {
    return (
      <form onSubmit={this.handleSubmit}>
        {this.renderInput("username", "Username")}
        {this.renderInput("password", "Password", "password")}
        {this.renderButton("Login")}
      </form>
    );
}

import React from "react";

const Input = ({ name, type, label, value, error, onChange }) => {
  return (
    <div className="form-group">
      <label htmlFor={name}>{label}</label>
      <input
        value={value}
        onChange={onChange}
        id={name}
        name={name}
        type={type}
        className="form-control"
      />
      {error && <div className="alert alert-danger">{error}</div>}
    </div>
  );
};

export default Input;

<input
  value={value}
  name={name}
  type={type}
  onChange={onChange}
  id={name}
  className="form-control"
/>

import React from "react";

const Input = ({ name, label, error, ...rest }) => {
  return (
    <div className="form-group">
      <label htmlFor={name}>{label}</label>
      <input {...rest} name={name} id={name} className="form-control" />
      {error && <div className="alert alert-danger">{error}</div>}
    </div>
  );
};

export default Input;

 import {Observable} from 'rxjs';

 import Rx from "rxjs/Rx";

 Rx.Observable.of(1, 2, 3).map(i => i.toString());

import { Observable } from "rxjs/Observable";
import "rxjs/add/observable/of";
import "rxjs/add/operator/map";

 Observable.of(1, 2, 3).map(i => i.toString());

import { Observable } from "rxjs/Observable";
import { of } from "rxjs/observable/of";
import { map } from "rxjs/operator/map";

 const source = of(1, 2, 3);
const mapped = map.call(source, i => i.toString());

 npm install rxjs-tslint-rules --save-dev

{
  "rulesDirectory": [
    "node_modules/codelyzer"
  ],
  "extends": [
    "rxjs-tslint-rules"
  ],  
  "rules": {
    "rxjs-add": { "severity": "error" },
    "rxjs-no-patched": { "severity": "error" },
    "rxjs-no-unused-add": { "severity": "error" },
    "rxjs-no-wholesale": { "severity": "error" },
    "rxjs-no-subject-unsubscribe": { "severity": "error" },

import 'rxjs/add/operator/map';
import 'rxjs/add/operator/do';
import 'rxjs/add/operator/catch';

// define the rxjs operators needed by your app
// see node_module/rxjs/Rx.js for more

// statics
import "rxjs/add/observable/from";
import "rxjs/add/observable/throw";

// operators
import "rxjs/add/operator/catch";
import "rxjs/add/operator/combineLatest";
import "rxjs/add/operator/debounceTime";
import "rxjs/add/operator/delay";
import "rxjs/add/operator/distinctUntilChanged";
import "rxjs/add/operator/do";
import "rxjs/add/operator/filter";
import "rxjs/add/operator/finally";
import "rxjs/add/operator/first";
import "rxjs/add/operator/ignoreElements";
import "rxjs/add/operator/let";
import "rxjs/add/operator/map";
import "rxjs/add/operator/mapTo";
import "rxjs/add/operator/mergeMap";
import "rxjs/add/operator/startWith";
import "rxjs/add/operator/switchMap";
import "rxjs/add/operator/takeUntil";
import "rxjs/add/operator/withLatestFrom";
import "rxjs/add/operator/takeUntil";
import "rxjs/add/operator/take";

 // import RxJs needed operators only once
import "./shared/rxjs-operators";

//...
@NgModule({
//...

 import { Observable } from "rxjs/Observable";

create table t1
(
col1 char(1),
col2 char(1)
)

create unique nonclustered index ix_uq on t1 (col1 , col2);

insert t1 
values('A', 'B'), ('B', 'C'), ('C', 'D'), ('D', 'E'), ('E', 'F'),
('G', 'H'), ('I', 'J'), ('K', 'L'), ('M', 'N'), ('O', 'P');

select col1 + col2
from t1
where col1 + col2 = 'OP'

select col1 + col2
from t1
where col1  = 'O' and col2 = 'P'

alter table t1 add col3 as col1 + col2 persisted

create clustered index ix1 on t1 (col3)

select *
from t1
where col3 = 'OP';

> npm i -g create-react-app
> create-react-app sample-30
> cd sample-30
> npm start

> npm install --save bootstrap

import "./App.css";

import React, { Component } from "react";

class App extends Component {
  state = { count: 0 };

  incrementCount = () => {
    this.setState({ count: this.state.count + 1 });
  };

  render() {
    return (
      <button onClick={this.incrementCount} className="btn btn-primary m-3">
        I was clicked {this.state.count} times!
      </button>
    );
  }
}

export default App;

//import App from "./App‍Class";
import App from "./AppFunction";

import React, { useState } from 'react';

const App = () => {
    const [count, setCount] = useState(0);

useState<number>(initialState: number | (() => number)): [number, React.Dispatch<React.SetStateAction<number>>]

import React, { useState } from "react";

const App = () => {
  const [count, setCount] = useState(0);
  const incrementCount = () => {
    setCount(count + 1);
  };

  return (
    <button onClick={incrementCount} className="btn btn-primary m-3">
      I was clicked {count} times!
    </button>
  );
};

export default App;

 const setCount: (value: React.SetStateAction<number>) => void

  incrementCount = () => {
    this.setState({ count: this.state.count + 1 });
  };

  incrementCount = () => {
    this.setState(prevState => ({
      count: prevState.count + 1
    }));
  };

  const incrementCount = () => {
    setCount(count + 1);
  };

const incrementCount = () => {
    setCount(prevCount => prevCount + 1);
  };

import "./App.css";

import React, { Component } from "react";

class App extends Component {
  state = {
    count: 0,
    isOn: false
  };

  incrementCount = () => {
    this.setState(prevState => ({
      count: prevState.count + 1
    }));
  };

  toggleLight = () => {
    this.setState(prevState => ({
      isOn: !prevState.isOn
    }));
  };

  render() {
    return (
      <>
        <h1>App Class</h1>
        <h2>Counter</h2>
        <button onClick={this.incrementCount} className="btn btn-primary m-3">
          I was clicked {this.state.count} times!
        </button>

        <h2>Toggle Light</h2>
        <div
          style={{
            height: "50px",
            width: "50px",
            cursor: "pointer"
          }}
          className={
            this.state.isOn ? "alert alert-info m-3" : "alert alert-warning m-3"
          }
          onClick={this.toggleLight}
        />
      </>
    );
  }
}

export default App;

import App from "./App‍Class";
//import App from "./AppFunction";

import React, { useState } from "react";

const App = () => {
  const [count, setCount] = useState(0);
  const [isOn, setIsOn] = useState(false);

  const incrementCount = () => {
    setCount(prevCount => prevCount + 1);
  };

  const toggleLight = () => {
    setIsOn(prevIsOn => !prevIsOn);
  };

  return (
    <>
      <h1>App Function</h1>
      <h2>Counter</h2>
      <button onClick={incrementCount} className="btn btn-primary m-3">
        I was clicked {count} times!
      </button>

      <h2>Toggle Light</h2>
      <div
        style={{
          height: "50px",
          width: "50px",
          cursor: "pointer"
        }}
        className={isOn ? "alert alert-info m-3" : "alert alert-warning m-3"}
        onClick={toggleLight}
      />
    </>
  );
};

export default App;

// import App from "./App‍Class";
import App from "./AppFunction";

import React, { useEffect, useState } from "react";

import React, { useEffect, useState } from "react";

const App = () => {
  const [count, setCount] = useState(0);

  useEffect(() => {
    document.title = `You have clicked ${count} times`;
  });

class App extends Component {

  componentDidMount() {
    document.title = `You have been clicked ${this.state.count} times`;
  }

  componentDidUpdate() {
    document.title = `You have been clicked ${this.state.count} times`;
  }

class App extends Component {

  componentDidMount() {
    // ...
    window.addEventListener("mousemove", this.handleMouseMove);
  }

  handleMouseMove = event => {
    this.setState({
      x: event.pageX,
      y: event.pageY
    });
  };

class App extends Component {
  state = {
    //...
    x: 0,
    y: 0
  };

<h2>Mouse Position</h2>
<p>X position: {this.state.x}</p>
<p>Y position: {this.state.y}</p>

  componentWillUnmount() {
    window.removeEventListener("mousemove", this.handleMouseMove);
  }

  const [mousePosition, setMousePosition] = useState({ x: 0, y: 0 });

  useEffect(() => {
    // ...
    window.addEventListener("mousemove", handleMouseMove);
  });

  const handleMouseMove = event => {
    setMousePosition({
      x: event.pageX,
      y: event.pageY
    });
  };

<h2>Mouse Position</h2>
{JSON.stringify(mousePosition, null, 2)}
<br />

  useEffect(() => {
    // …
    // componentDidMount & componentDidUpdate
    window.addEventListener("mousemove", handleMouseMove);

    // componentWillUnmount
    return () => {
      window.removeEventListener("mousemove", handleMouseMove);
    };
  });

  useEffect(() => {
    document.title = `You have clicked ${count} times`;
    window.addEventListener("mousemove", handleMouseMove);

    return () => {
      window.removeEventListener("mousemove", handleMouseMove);
    };
  },[]);

  useEffect(() => {
   // ...
  },[count]);

const [status, setStatus] = useState(navigator.onLine);

  useEffect(() => {
    // ...

    window.addEventListener("online", handleOnline);
    window.addEventListener("offline", handleOffline);

    return () => {
      // ...
  
      window.removeEventListener("online", handleOnline);
      window.removeEventListener("offline", handleOffline);
    };
  }, [count]);

  const handleOnline = () => {
    setStatus(true);
  };

  const handleOffline = () => {
    setStatus(false);
  };

<h2>Network Status</h2>
<p>
  You are <strong>{status ? "online" : "offline"}</strong>
</p>

const initialLocationState = {
  latitude: null,
  longitude: null,
  speed: null
};

const App = () => {
  // ...
  const [location, setLocation] = useState(initialLocationState);

  useEffect(() => {
    // ...

    navigator.geolocation.getCurrentPosition(handleGeolocation);
    const watchId = navigator.geolocation.watchPosition(handleGeolocation);

    return () => {
      // ...
      navigator.geolocation.clearWatch(watchId);
    };
  }, [count]);

  let mounted = true;

  useEffect(() => {
   // ...

    return () => {
      // ...
      mounted = false;
    };
  }, [count]);

  const handleGeolocation = event => {
    if (mounted) {
      setLocation({
        latitude: event.coords.latitude,
        longitude: event.coords.longitude,
        speed: event.coords.speed
      });
    }
  };

<h2>Geolocation</h2>
<p>Latitude is {location.latitude}</p>
<p>Longitude is {location.longitude}</p>
<p>Your speed is {location.speed ? location.speed : "0"}</p>

const [{ latitude, longitude, speed }, setLocation] = useState(
    initialLocationState
  );

<h2>Geolocation</h2>
<p>Latitude is {latitude}</p>
<p>Longitude is {longitude}</p>
<p>Your speed is {speed ? speed : "0"}</p>