Tutorial by Examples: o

Create enum of custom errors enum RegistrationError: Error { case invalidEmail case invalidPassword case invalidPhoneNumber } Create extension of RegistrationError to handle the Localized description. extension RegistrationError: LocalizedError { public var errorDescription...

public function someAction(){ // Action's code return new Response($error, 500); } Another example: public function someAction(){ // Action's code $response = new Response(); $response->setStatusCode(500) $response->setContent($content); ...

Return JSON formated response: use Symfony\Component\HttpFoundation\JsonResponse; public function someAction(){ // Action's code $data = array( // Array data ); return new JsonResponse($data); }

In this example, User Table will have a column that references the Agency table. CREATE TABLE agencies ( -- first create the agency table id SERIAL PRIMARY KEY, name TEXT NOT NULL ) CREATE TABLE users ( id SERIAL PRIMARY KEY, agency_id NOT NULL INTEGER REFERENCES agencies(id) DEFERR...

Sometimes, we want some fields in the JSON string to be optional. For example, data Person = Person { firstName :: Text , lastName :: Text , age :: Maybe Int } This can be achieved by import Data.Aeson.TH $(deriveJSON ...

The expiration values of a key can be managed by a user outside of the update commands. Redis allows a user to determine the current time to live (TTL) of a key using the TTL command: TTL key This command will return the TTL of a key in seconds or will return the special values -1 or -2. A -1 ...

wire d = 1'bx; // say from previous block. Will be 1 or 0 in hardware if (d == 1'b) // false in simulation. May be true of false in hardware

Typescript allow to re-export declarations. //Operator.ts interface Operator { eval(a: number, b: number): number; } export default Operator; //Add.ts import Operator from "./Operator"; export class Add implements Operator { eval(a: number, b: number): number { ...

Simple Hello World Application: using System; namespace HelloWorld { class Program { static void Main(string[] args) { Console.WriteLine("Hello World"); } } } Equivalent IL Code (which will be JIT compiled) // Microsoft (R) ...

Retrolambda lets you run Java 8 code with lambda expressions, method references and try-with-resources statements on Java 7, 6 or 5. It does this by transforming your Java 8 compiled bytecode so that it can run on an older Java runtime. Backported Language Features: Lambda expressions are back...

It is possible to use integer variables with latex. To create a new variable we need the \newcounter{name} command, where name is the name of the new counter. The name must contain only letters. This command creates a new one with name \thename. With this command we can print name variable onto the ...

Completion can be used to match words used in a document. When typing a word, Ctrlp or Ctrln will match previous or next similar words in the document. This can even be combined with Ctrl-X mode to complete entire lines. For instance type something like: This is an example sentence. then go to ...

package com.test.ws.example; import javax.xml.soap.MessageFactory; import javax.xml.soap.MimeHeaders; import javax.xml.soap.SOAPBody; import javax.xml.soap.SOAPConnection; import javax.xml.soap.SOAPConnectionFactory; import javax.xml.soap.SOAPElement; import javax.xml.soap.SOAPEnve...

This example shows how to use mathematical operations with counters. It may be useful for loops in latex. Addition: \addtocounter{num}{n} this command adds n to num, where num is a counter and n is a positive integer. Subtraction: \addtocounter{num}{-n} this command subtracts n from num, where n...

C++03 Declares a variable to have automatic storage duration. It is redundant, since automatic storage duration is already the default at block scope, and the auto specifier is not allowed at namespace scope. void f() { auto int x; // equivalent to: int x; auto y; // illegal in C++; ...

There are certain principles that apply to optimization in any computer language, and Python is no exception. Don't optimize as you go: Write your program without regard to possible optimizations, concentrating instead on making sure that the code is clean, correct, and understandable. If it's too...

Copy the database from the emulator/phone to view it. It can be done by using ADB: adb pull /data/data/<packagename>/files/ That command will pull all Realm files created by Realm.getInstance(getContext()) or Realm.getInstance(new RealmConfiguration.Builder(context).build()). The default d...

Nested for loops may be used to iterate over a number of unique iterables. result = [] for a = iterable_a for b = iterable_b push!(result, expression) end end Similarly, multiple iteration specifications may be supplied to an array comprehension. [expression for a = iterabl...

Generator comprehensions follow a similar format to array comprehensions, but use parentheses () instead of square brackets []. (expression for element = iterable) Such an expression returns a Generator object. julia> (x^2 for x = 1:5) Base.Generator{UnitRange{Int64},##1#2}(#1,1:5) Fun...

&& chains two commands. The second one runs only if the first one exits with success. || chains two commands. But second one runs only if first one exits with failure. [ a = b ] && echo "yes" || echo "no" # if you want to run more commands within a logical c...