Tutorial by Examples: i

Multidex by extending Application

Use this option if your project requires an Application subclass. Specify this Application subclass using the android:name property in the manifest file inside the application tag. In the Application subclass, add the attachBaseContext() method override, and in that method call MultiDex.install():...

Android • Multidex and the Dex Method Limit

ReactJS component written in Typescript

You can use ReactJS's components easily in TypeScript. Just rename the 'jsx' file extension to 'tsx': //helloMessage.tsx: var HelloMessage = React.createClass({ render: function() { return <div>Hello {this.props.name}</div>; } }); ReactDOM.render(<HelloMessage name=&q...

TypeScript • Using Typescript with React (JS & native)

Inline with



            
            
If a sentence contains computer code (for example, the name of an HTML element), use the code element to mark it up:
&lt;p&gt;The &lt;code&gt;a&lt;/code&gt; element creates a hyperlink.&lt;/p&gt;


            

            
            
                
                    
                        HTML
                        •
                        Marking up computer code





    

        

            
            
                
                    Block with  and 
                

            


            
            
If the formatting (white space, new lines, indentation) of the code matters, use the pre element in combination with the code element:
&lt;pre&gt;
    &lt;code&gt;
    x = 42
    if x == 42:
        print &quot;x is …          … 42&quot;
    &lt;/code&gt;
&lt;/pre&gt;

You still have to esc...            

            
            
                
                    
                        HTML
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                        Marking up computer code
                        
                    
                    
                
            
        

    





    

        

            
            
                
                    Not matching a given string
                
            

            
            
To match something that does not contain a given string, one can use negative lookahead:
Regex syntax: (?!string-to-not-match)
Example:
//not matching &quot;popcorn&quot;
String regexString = &quot;^(?!popcorn).*$&quot;;
System.out.println(&quot;[popcorn] &quot; + (&quot;popcorn&quot;.matches(r...            

            
            
                
                    
                        Java Language
                        •
                        Regular Expressions
                        
                    
                    
                
            
        
    




    

        

            
            
                
                    Integration Tests
                
            

            
            
lib.rs:
pub fn to_test(output: bool) -&gt; bool {
    output
}

Each file in the tests/ folder is compiled as single crate.
tests/integration_test.rs
extern crate test_lib;
use test_lib::to_test;

#[test]
fn test_to_test(){
    assert_eq!(to_test(true), true);
}


            

            
            
                
                    
                        Rust
                        •
                        Tests
                        
                    
                    
                
            
        
    




    

        

            
            
                
                    Column selection of a group
                
            

            
            
When you do a groupby you can select either a single column or a list of columns:
In [11]: df = pd.DataFrame([[1, 1, 2], [1, 2, 3], [2, 3, 4]], columns=[&quot;A&quot;, &quot;B&quot;, &quot;C&quot;])

In [12]: df
Out[12]:
   A  B  C
0  1  1  2
1  1  2  3
2  2  3  4

In [13]: g = df.groupby(...            

            
            
                
                    
                        pandas
                        •
                        Grouping Data
                        
                    
                    
                
            
        
    




    

        

            
            
                
                    Custom string interpolators
                
            

            
            
It is possible to define custom string interpolators in addition to the built-in ones.
my&quot;foo${bar}baz&quot;

Is expanded by the compiler to:
new scala.StringContext(&quot;foo&quot;, &quot;baz&quot;).my(bar)

scala.StringContext has no my method, therefore it can be provided by implicit c...            

            
            
                
                    
                        Scala Language
                        •
                        String Interpolation
                        
                    
                    
                
            
        
    




    

        

            
            
                
                    Using a Template Engine
                
            

            
            
Using a Template Engine
The following code will setup Jade as template engine. (Note: Jade has been renamed to pug as of December 2015.)
const express = require('express');  //Imports the express module
const app = express();  //Creates an instance of the express module

const PORT = 3000; //Ra...            

            
            
                
                    
                        Node.js
                        •
                        Web Apps With Express
                        
                    
                    
                
            
        
    




    

        

            
            
                
                    Fused location API
                
            

            
            
Example Using Activity w/ LocationRequest
/*
 * This example is useful if you only want to receive updates in this 
 * activity only, and have no use for location anywhere else.
 */
public class LocationActivity extends AppCompatActivity implements
        GoogleApiClient.ConnectionCallbacks, ...            

            
            
                
                    
                        Android
                        •
                        Location
                        
                    
                    
                
            
        
    




    

        

            
            
                
                    Databinding in Fragment
                
            

            
            
Data Model
public class Item {
    private String name;

    public String getName() {
        return name;
    }

    public void setName(String name){
        this.name = name;
    }

}

Layout XML
&lt;?xml version=&quot;1.0&quot; encoding=&quot;utf-8&quot;?&gt;
&lt;layout xmlns:an...            

            
            
                
                    
                        Android
                        •
                        Data Binding Library
                        
                    
                    
                
            
        
    




    

        

            
            
                
                    Parsing JSON property to enum with Gson
                
            

            
            
If you want to parse a String to enum with Gson:

{&quot;status&quot; : &quot;open&quot;}

public enum Status {
    @SerializedName(&quot;open&quot;)
    OPEN,
    @SerializedName(&quot;waiting&quot;)
    WAITING,
    @SerializedName(&quot;confirm&quot;)
    CONFIRM,
    @SerializedName(&...            

            
            
                
                    
                        Android
                        •
                        Gson
                        
                    
                    
                
            
        
    




    

        

            
            
                
                    Show Size of All Tables in Current Database 
                
            

            
            
SELECT
    s.name + '.' + t.NAME AS TableName,
    SUM(a.used_pages)*8 AS 'TableSizeKB'  --a page in SQL Server is 8kb
FROM sys.tables t
    JOIN sys.schemas s on t.schema_id = s.schema_id
    LEFT JOIN sys.indexes i ON t.OBJECT_ID = i.object_id
    LEFT JOIN sys.partitions p ON i.object_id = ...            

            
            
                
                    
                        Microsoft SQL Server
                        •
                        Retrieve information about the database
                        
                    
                    
                
            
        
    




    

        

            
            
                
                    Installation or Setup
                
            

            
            
Since JUnit is a Java library, all you have to do to install it is to add a few JAR files into the classpath of your Java project and you're ready to go.
You can download these two JAR files manually: junit.jar &amp; hamcrest-core.jar.
If you're using Maven, you can simply add in a dependency into...            

            
            
                
                    
                        junit
                        •
                        Getting started with junit
                        
                    
                    
                
            
        
    




    

        

            
            
                
                    Caller info attributes
                
            

            
            
Caller info attributes can be used to pass down information about the invoker to the invoked method. The declaration looks like this:
using System.Runtime.CompilerServices;

public void LogException(Exception ex,
                         [CallerMemberName]string callerMemberName = &quot;&quot;,
...            

            
            
                
                    
                        C# Language
                        •
                        Attributes
                        
                    
                    
                
            
        
    




    

        

            
            
                
                    Optional and Default Parameters
                
            

            
            
Optional Parameters
In TypeScript, every parameter is assumed to be required by the function. You can add a ? at the end of a parameter name to set it as optional.
For example, the lastName parameter of this function is optional:
function buildName(firstName: string, lastName?: string) {
    // ...            

            
            
                
                    
                        TypeScript
                        •
                        Functions
                        
                    
                    
                
            
        
    




    

        

            
            
                
                    Converting to boolean
                
            

            
            
Boolean(...) will convert any data type into either true or false.
Boolean(&quot;true&quot;) === true
Boolean(&quot;false&quot;) === true
Boolean(-1) === true
Boolean(1) === true
Boolean(0) === false
Boolean(&quot;&quot;) === false
Boolean(&quot;1&quot;) === true
Boolean(&quot;0&quot;) === t...            

            
            
                
                    
                        JavaScript
                        •
                        Variable coercion/conversion
                        
                    
                    
                
            
        
    




    

        

            
            
                
                    Define primary, primary dark, and accent colors
                
            

            
            
You can customize your theme’s color palette.
Using framework APIs
5.0
&lt;style name=&quot;AppTheme&quot; parent=&quot;Theme.Material&quot;&gt;
    &lt;item name=&quot;android:colorPrimary&quot;&gt;@color/primary&lt;/item&gt;
    &lt;item name=&quot;android:colorPrimaryDark&quot;&gt;@color/pri...            

            
            
                
                    
                        Android
                        •
                        Theme, Style, Attribute
                        
                    
                    
                
            
        
    




    

        

            
            
                
                    Use Custom Theme Per Activity
                
            

            
            
In themes.xml:
&lt;style name=&quot;MyActivityTheme&quot; parent=&quot;Theme.AppCompat&quot;&gt;
    &lt;!-- Theme attributes here --&gt;
&lt;/style&gt;

In AndroidManifest.xml:
&lt;application
    android:icon=&quot;@mipmap/ic_launcher&quot;
    android:label=&quot;@string/app_name&quot;
 ...            

            
            
                
                    
                        Android
                        •
                        Theme, Style, Attribute
                        
                    
                    
                
            
        
    




    

        

            
            
                
                    Installation
                
            

            
            
Have required JavaScript and CSS files included in your index.html. You can do this by either using the CDN files availiable at the following paths:
&lt;link rel=&quot;stylesheet&quot; type=&quot;text/css&quot; href=&quot;//cdn.datatables.net/1.10.12/css/jquery.dataTables.css&quot;&gt;
  
&lt;scr...            

            
            
                
                    
                        datatables
                        •
                        Getting started with datatables