Tutorial by Topics: v

Pivot query creation in MySQL relies upon the GROUP_CONCAT() function. If the result of the expression that creates the columns of the pivot query is expected to be large, the value of the group_concat_max_len variable must be increased: set session group_concat_max_len = 1024 * 1024; -- This sho...

Content providers manage access to a structured set of data. They encapsulate the data, and provide mechanisms for defining data security. Content providers are the standard interface that connects data in one process with code running in another process. When you want to access data in a content...

An expression can be explicitly converted or cast to type T using dynamic_cast<T>, static_cast<T>, reinterpret_cast<T>, or const_cast<T>, depending on what type of cast is intended. C++ also supports function-style cast notation, T(expr), and C-style cast notation, (T)expr. ...

config.vm.provision "shell", inline: COMMANDS config.vm.provision "shell", path: "relativePath/script.sh" ParameterDetailsCOMMANDSThe shell commands to run. Can be a string (e.g. "echo \"Hello, World!\"") or a string variable (e.g. $setup). ...

Inside a specific node /path to/element[@attribute_name] Anywhere in the document //*[@attribute_name] Inside a specific node with some value /path to/element[@attribute_name='search value'] /path to/element[@attribute_name="search value"] Anywhere in the documen...

Source: What is the difference between a definition and a declaration? Source (For weak and strong symbols): https://www.amazon.com/Computer-Systems-Programmers-Perspective-2nd/dp/0136108040/

What is Functional Programming ? Functional Programming or FP is a programming paradigm that is built upon two main concepts immutability, and statelessness.The goal behind FP is to make your code more readable, reusable, and portable. What is Functional JavaScript There has been a debate to ca...

The most common pitfall with scope arises in parallelization. All variables and functions must be passed into a new environment that is run on each thread.

session$sendCustomMessage(name,list of parameters) Shiny.addCustomMessageHandler(name, JS function that accepts list of parameters) Shiny.onInputChange(name,value)

ParameterDetailsPORTPort that the Meteor app will be available on.MONGO_URLURL to connect to the Mongo instance.ROOT_URL...OPLOG_URL...MONGO_OPLOG_URL...METEOR_ENV...NODE_ENV...NODE_OPTIONS...DISABLE_WEBSOCKETS...MAIL_URL...DDP_DEFAULT_CONNECTION_URL...HTTP_PROXY...HTTPS_PROXY...METEOR_OFFLINE_CATA...

As val are semantically static, they are initialized "in-place" wherever they appear in the code. This can produce surprising and undesirable behavior when used in abstract classes and traits. For example, let's say we would like to make a trait called PlusOne that defines an increment ...