Tutorial by Examples: ti

public interface IShape { decimal Area(); } public struct Rectangle : IShape { public decimal Length { get; set; } public decimal Width { get; set; } public decimal Area() { return Length * Width; } }

Django default project layout creates a single settings.py. This is often useful to split it like this: myprojectroot/ myproject/ __init__.py settings/ __init__.py base.py dev.py prod.py tests.py This enables...

SELECT FIND_IN_SET('b','a,b,c'); Return value: 2 SELECT FIND_IN_SET('d','a,b,c'); Return value: 0

Assuming a class from django.db import models class Author(models.Model): name = models.CharField(max_length=50) def __str__(self): return self.name def get_absolute_url(self): return reverse('view_author', args=[str(self.id)]) class Book(models.Mo...

tl;dr : Create a base class that defines two user objects (say user and another_user). Create your other models and define three Client instances. self.client : Representing user logged in browser self.another_client : Representing another_user 's client self.unlogged_client : Representing unlo...

To run a container interactively, pass in the -it options: $ docker run -it ubuntu:14.04 bash root@8ef2356d919a:/# echo hi hi root@8ef2356d919a:/# -i keeps STDIN open, while -t allocates a pseudo-TTY.

In some cases you may want to wrap a synchronous operation inside a promise to prevent repetition in code branches. Take this example: if (result) { // if we already have a result processResult(result); // process it } else { fetchResult().then(processResult); } The synchronous and async...

When you want to use user generated content in the SQL, it with done with parameters. For example for searching user with the name aminadav you should do: var username = 'aminadav'; var querystring = 'SELECT name, email from users where name = ?'; connection.query(querystring, [username], functi...

a. Running multiple queries at same time All queries in MySQL connection are done one after another. It means that if you want to do 10 queries and each query takes 2 seconds then it will take 20 seconds to complete whole execution. The solution is to create 10 connection and run each query in a di...

You send the query as a string and in response callback with the answer is received. The callback gives you error, array of rows and fields. Each row contains all the column of the returned table. Here is a snippet for the following explanation. connection.query('SELECT name,email from users', fu...

You can use a RecyclerView.ItemDecoration to put extra margins around each item in a RecyclerView. This can in some cases clean up both your adapter implementation and your item view XML. public class MyItemDecoration extends RecyclerView.ItemDecoration { private final int extraMargin; ...

You can group multiple boolean logic statements within parenthesis in order to create a more complex logic evaluation, especially useful in if statements. if ((age >= 18 && height >= 5.11) || (status === 'royalty' && hasInvitation)) { console.log('You can enter our club'); ...

__call() and __callStatic() are called when somebody is calling nonexistent object method in object or static context. class Foo { /** * This method will be called when somebody will try to invoke a method in object * context, which does not exist, like: * * $foo->...

With Blade, you can also include partial views (called 'partials') directly into a page like so: @include('includes.info', ['title' => 'Information Station']) The code above will include the view at 'views/includes/info.blade.php'. It will also pass in a variable $title having value 'Informat...

With local image Swift let image = UIImage(named: "imageFromBundleOrAsset") Objective-C UIImage *image = [UIImage imageNamed:@"imageFromBundleOrAsset"]; Note The method imageNamed caches the image's contents to memory. Loading many large images that way can cause low...

Just like char and int, a function is a fundamental feature of C. As such, you can declare a pointer to one: which means that you can pass which function to call to another function to help it do its job. For example, if you had a graph() function that displayed a graph, you could pass which functio...

Create a class which extends Service class and in overridden method onBind return your local binder instance: public class LocalService extends Service { // Binder given to clients private final IBinder mBinder = new LocalBinder(); /** * Class used for the client Binder. Bec...

Describe your service access interface through .aidl file: // IRemoteService.aidl package com.example.android; // Declare any non-default types here with import statements /** Example service interface */ interface IRemoteService { /** Request the process ID of this service, to do evil...

SharedPreferences Manager (Singleton) class to read and write all types of data. import android.content.Context; import android.content.SharedPreferences; import android.util.Log; import com.google.gson.Gson; import java.lang.reflect.Type; /** * Singleton Class for accessing SharedPref...

This is an extension of Basic Example: Basic Structure import React, { Component } from 'react'; import { render } from 'react-dom'; class FirstComponent extends Component { render() { return ( <div> Hello, {this.props.name}! I am a FirstCompon...