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# lib/mix/tasks/mytask.ex defmodule Mix.Tasks.MyTask do use Mix.Task @shortdoc "A simple mix task" def run(_) do IO.puts "YO!" end end Compile and run: $ mix compile $ mix my_task "YO!"

Simple item insertion can be done with Array.prototype.splice method: arr.splice(index, 0, item); More advanced variant with multiple arguments and chaining support: /* Syntax: array.insert(index, value1, value2, ..., valueN) */ Array.prototype.insert = function(index) { this.splice.a...

// Uses Windows authentication. Replace the Trusted_Connection parameter with // User Id=...;Password=...; to use SQL Server authentication instead. You may // want to find the appropriate connection string for your server. string connectionString = @"Server=myServer\myInstance;Database=myDa...

#!/usr/bin/env perl use strict; use warnings 'all'; use XML::Twig; my $twig = XML::Twig->parse( \*DATA ); #we can use the 'root' method to find the root of the XML. my $root = $twig->root; #first_child finds the first child element matching a value. my $title = $root->firs...

Used to declare an object or function that is defined elsewhere (and that has external linkage). In general, it is used to declare an object or function to be used in a module that is not the one in which the corresponding object or function is defined: /* file1.c */ int foo = 2; /* Has externa...

The year, month or day components of a DATE data type can be found using the EXTRACT( [ YEAR | MONTH | DAY ] FROM datevalue ) SELECT EXTRACT (YEAR FROM DATE '2016-07-25') AS YEAR, EXTRACT (MONTH FROM DATE '2016-07-25') AS MONTH, EXTRACT (DAY FROM DATE '2016-07-25') AS DAY FROM D...

Concatenating strings using a StringBuilder can offer performance advantages over simple string concatenation using +. This is due to the way memory is allocated. Strings are reallocated with each concatenation, StringBuilders allocate memory in blocks only reallocating when the current block is e...

var regExp = new RegExp(r"(\w+)"); var str = "Parse my string"; Iterable<Match> matches = regExp.allMatches(str); It's a good idea to use "raw strings" (prefix with r) when writing regular expressions so you can use unescaped backslashes in your expression. ...

I like to wrap my OkHttp into a class called HttpClient for example, and in this class I have methods for each of the major HTTP verbs, post, get, put and delete, most commonly. (I usually include an interface, in order to keep for it to implement, in order to be able to easily change to a different...

Lambdas are meant to provide inline implementation code for single method interfaces and the ability to pass them around as we have been doing with normal variables. We call them Functional Interface. For example, writing a Runnable in anonymous class and starting a Thread looks like: //Old way n...

In your Storyboard, add a UITableView object on your UIViewController and let it cover the entire view. Setup the UITableviewDataSource and UITableviewDelegate connections. Objective-C In your .h file NSMutableArray *arrayForBool; NSMutableArray *sectionTitleArray; In your .m file - (void)vi...

#!/bin/bash expr 1 + 2 Output: 3

Use "-x" to enable debug output of executed lines. It can be run on an entire session or script, or enabled programmatically within a script. Run a script with debug output enabled: $ bash -x myscript.sh Or $ bash --debug myscript.sh Turn on debugging within a bash script. It may ...

Exit status 0: success Exit status other than 0: failure To test on the exit status of a command: if command;then echo 'success' else echo 'failure' fi

expr or Evaluate expressions evaluates an expression and writes the result on standard output Basic arithmetics expr 2 + 3 5 When multiplying, you need to escape the * sign expr 2 \* 3 6 You can also use variables a=2 expr $a + 3 5 Keep in mind that it only supports integers, so exp...

NOTE: This is only available in Scala 2.12+ (and in recent 2.11.x versions with the -Xexperimental -Xfuture compiler flags) A SAM type can be implemented using a lambda: 2.11.8 trait Runnable { def run(): Unit } val t: Runnable = () => println("foo") The type can optional...

Setup First, install the necessary packages with: npm install express cors mongoose Code Then, add dependencies to server.js, create the database schema and the name of the collection, create an Express.js server, and connect to MongoDB: var express = require('express'); var cors = require('...

The following example uses Express to create an HTTP server listening on port 3000, which responds with "Hello, World!". Express is a commonly-used web framework that is useful for creating HTTP APIs. First, create a new folder, e.g. myApp. Go into myApp and make a new JavaScript file con...

<svg width="900px" height="400px" viewBox="900 400"> <defs> <filter id="GaussianHardEdge" > <feConvolveMatrix order="3" kernelMatrix=" 1 1 1 1 1 1 ...

<svg width="800px" height="600px"> <defs> <filter id="complex-shadow" color-interpolation-filters="sRGB" x="-50%" y="-50%" height="200%" width="200%"> <!-- Take source alpha, offset it by angle/...