Tutorial by Examples: ti

Merging Publications

Publications can be merged on the client, resulting in differently shaped documents within a single cursor. The following example represents how a user directory might publish a minimal amount of public data for users of an app, and provide a more detailed profile for the logged in user. // client...

meteor • Publishing Data

Splitting a String into an Array

In Swift you can easily separate a String into an array by slicing it at a certain character: 3.0 let startDate = "23:51" let startDateAsArray = startDate.components(separatedBy: ":") // ["23", "51"]` 2.2 let startDate = "23:51" let sta...

Swift Language • Strings and Characters

Replica Set Configuration

Then go into the mongo shell and initiate the replica set, like so: meteor mongo > rs.initiate() PRIMARY> rs.add("mongo-a") PRIMARY> rs.add("mongo-b") PRIMARY> rs.add("mongo-c") PRIMARY> rs.setReadPref('secondaryPreferred')

meteor • Replica Sets and Sharding

PDF and PMF for different distributions in R

PMF FOR THE BINOMIAL DISTRIBUTION Suppose that a fair die is rolled 10 times. What is the probability of throwing exactly two sixes? You can answer the question using the dbinom function: > dbinom(2, 10, 1/6) [1] 0.29071 PMF FOR THE POISSON DISTRIBUTION The number of sandwhich ordered in ...

R Language • Probability Distributions with R

R in Latex with Knitr and Code Externalization

Knitr is an R package that allows us to intermingle R code with LaTeX code. One way to achieve this is external code chunks. External code chunks allow us to develop/test R Scripts in an R development environment and then include the results in a report. It is a powerful organizational technique....

R Language • R in LaTeX with knitr

Sorting arrays

Sorting arrays can be easily done with the Arrays api. import java.util.Arrays; // creating an array with integers int[] array = {7, 4, 2, 1, 19}; // this is the sorting part just one function ready to be used Arrays.sort(array); // prints [1, 2, 4, 7, 19] System.out.println(Arrays.toString...

Java Language • Arrays

Steps to use custom fonts in React Native (Android)

Paste your fonts file inside android/app/src/main/assets/fonts/font_name.ttf Recompile the Android app by running react-native run-android Now, You can use fontFamily: 'font_name' in your React Native Styles

react-native • Custom Fonts

Partial Application

Similar to currying, partial application is used to reduce the number of arguments passed to a function. Unlike currying, the number need not go down by one. Example: This function ... function multiplyThenAdd(a, b, c) { return a * b + c; } ... can be used to create another function that...

JavaScript • Functions

Static class members

A class is also allowed to have static members, which can be either variables or functions. These are considered to be in the class' scope, but aren't treated as normal members; they have static storage duration (they exist from the start of the program to the end), aren't tied to a particular inst...

C++ • Classes/Structures

Join parent and child JSON entities using CROSS APPLY OPENJSON

Join parent objects with their child entities, for example we want a relational table of each person and their hobbies DECLARE @json nvarchar(1000) = N'[ { "id":1, "user":{"name":"John"}, "hobbies":[ {...

Microsoft SQL Server • JSON in Sql Server

Programmatically adding a metadata endpoint to a service

When you also want to expose metadata without a config file you can build on the example programmatically creating a ServiceHost: public ConsoleHost() { mHost = new ServiceHost(typeof(Example), new Uri("http://localhost:8000/Example"), new Uri("net.tcp://9000/Example")); ...

wcf • Your first service

Place allocation and cleanup code next to each other

Scope guards allow executing statements at certain conditions if the current block is left. import core.stdc.stdlib; void main() { int* p = cast(int*)malloc(int.sizeof); scope(exit) free(p); }

D Language • Scope guards

Multiple, nested scopes

import std.stdio; void main() { writeln("<html>"); scope(exit) writeln("</html>"); { writeln("\t<head>"); scope(exit) writeln("\t</head>"); "\t\t<title>%s</title>".write...

D Language • Scope guards

Unit Testing Promises with Mocha, Sinon, Chai and Proxyquire

Here we have a simple class to be tested that returns a Promise based on the results of an external ResponseProcessor that takes time to execute. For simplicty we'll assume that the processResponse method won't ever fail. import {processResponse} from '../utils/response_processor'; const ping =...

JavaScript • Unit Testing Javascript

Selective imports

Selective imports can help to cleanup the namespace and speed-up the compile-time even more, because the compiler only needs to parse the specific, selected functions. import std.stdio: writeln; void main() { writeln("Hello world"); }

D Language • Imports and modules

Renamed and selective imports

Selective imports may also be renamed. void main() { import std.stdio : fooln = writeln; fooln("Hello world"); }

D Language • Imports and modules

Module declaration

Modules have a one-to-one correspondence with source files. The module name is, by default, the file name with the path and extension stripped off, and can be set explicitly with the module declaration. The ModuleDeclaration sets the name of the module and what package it belongs to. If absent, the...

D Language • Imports and modules

Using move semantics on containers

You can move a container instead of copying it: void print(const std::vector<int>& vec) { for (auto&& val : vec) { std::cout << val << ", "; } std::cout << std::endl; } int main() { // initialize vec1 with 1, 2, 3, 4 and...

C++ • Move Semantics

How to use the strftime method

Converting a time to a string is a pretty common thing to do in Ruby. strftime is the method one would use to convert time to a string. Here are some examples: Time.now.strftime("%Y-%m-d %H:%M:S") #=> "2016-07-27 08:45:42" This can be simplified even further Time.now.str...

Ruby Language • Time

Multiline modifier

By default, the caret ^ metacharacter matches the position before the first character in the string. Given the string "charsequence" applied against the following patterns: /^char/ & /^sequence/, the engine will try to match as follows: /^char/ ^ - charsequence c - charsequ...

Regular Expressions • Anchor Characters: Caret (^)