Tutorial by Examples: s

Named Functions defmodule Math do # one way def add(a, b) do a + b end # another way def subtract(a, b), do: a - b end iex> Math.add(2, 3) 5 :ok iex> Math.subtract(5, 2) 3 :ok Private Functions defmodule Math do def sum(a, b) do a...

Guard clauses enables us to check the arguments before executing the function. Guard clauses are usually preferred to if and cond due to their readability, and to make a certain optimization technique easier for the compiler. The first function definition where all guards match is executed. Here is...

You can pass default parameters to any named function using the syntax: param \\ value: defmodule Example do def func(p1, p2 \\ 2) do IO.inspect [p1, p2] end end Example.func("a") # => ["a", 2] Example.func("b", 4) # => ["b", ...

C99 Type Declaration A structure with at least one member may additionally contain a single array member of unspecified length at the end of the structure. This is called a flexible array member: struct ex1 { size_t foo; int flex[]; }; struct ex2_header { int foo; char...

Enable USB Debugging on your device and from command line type adb devices. If everything is OK, the response should be: List of devices attached 1234567890 device Where 1234567890 is the device's id. If multiple devices are connected, you should see all of them: List of devices at...

Named vector can be created in several ways. With c: xc <- c('a' = 5, 'b' = 6, 'c' = 7, 'd' = 8) which results in: > xc a b c d 5 6 7 8 with list: xl <- list('a' = 5, 'b' = 6, 'c' = 7, 'd' = 8) which results in: > xl $a [1] 5 $b [1] 6 $c [1] 7 $d [1] 8 Wi...

Binding is the process of assigning an object to an identifier or variable name. Early binding (also known as static binding) is when an object declared in Excel is of a specific object type, such as a Worksheet or Workbook. Late binding occurs when general object associations are made, such as the ...

To clone a specific branch of a repository, type --branch <branch name> before the repository url: git clone --branch <branch name> <url> [directory] To use the shorthand option for --branch, type -b. This command downloads entire repository and checks out <branch name>. ...

A sequence is a series of elements that can be enumerated. It is an alias of System.Collections.Generic.IEnumerable and lazy. It stores a series of elements of the same type (can be any value or object, even another sequence). Functions from the Seq.module can be used to operate on it. Here is a s...

template<class InputIterator, class Function> Function for_each(InputIterator first, InputIterator last, Function f); Effects: Applies f to the result of dereferencing every iterator in the range [first, last) starting from first and proceeding to last - 1. Parameters: first, last -...

First you need to install and start your Redis server, check the link below that can help you to install redis on you server or local machine. Installation and Setup Now open your command prompt and run command redis-cli : To save first set >SET 'keyname' then 'value' 127.0.0.1:6379> SET h...

To change password of current user just type: sudo passwd It will ask you to enter your current password: [sudo] password for <user>: And then you will be asked to enter new password: Enter new UNIX password: And finally you will be asked to re-enter your password: Retype new UNIX...

//Swift let fooViewController = UIViewController() navigationController?.pushViewController(fooViewController, animated: true) //Objective-C UIViewController *fooViewController = [[UIViewController alloc] init]; [navigationController pushViewController:fooViewController animated:YES];

As we know that we should use synchronized keyword to make execution of a method or block exclusive. But few of us may not be aware of one more important aspect of using synchronized and volatile keyword: apart from making a unit of code atomic, it also provides read / write barrier. What is this re...

Go to editor (from tool window) Esc Switching focus to corresponding tool window Windows: Alt + <tool window number> OS X / macOS: Cmd + <tool window number> For example switching focus to the project window Windows: Alt + 1 OS X / macOS: Cmd + 1 Recent files popup Windows: Ctrl...

It is common within applications to need to have code like this : a = a + 1 or a = a * 2 There is an effective shortcut for these in place operations : a += 1 # and a *= 2 Any mathematic operator can be used before the '=' character to make an inplace operation : -= decrement the va...

YAML is a text based format allowing to store structured data in a hierarchy. YAML is designed to be human and machine readable with a minimum of overhead. The YAML specification can be found at yaml.org. There is also a reference card Comments start with # and go till newline, comments must be sep...

If you've got multiple implementations of the same interface, Spring can autowire them all into a collection object. I'm going to use an example using a Validator pattern1 Foo Class: public class Foo { private String name; private String emailAddress; private String errorMessage;...

All of the Bitwise operators (except ~) have their own in place versions a = 0b001 a &= 0b010 # a = 0b000 a = 0b001 a |= 0b010 # a = 0b011 a = 0b001 a <<= 2 # a = 0b100 a = 0b100 a >>= 2 # a = 0b001 a = 0b101 a ^= 0b011 # a = 0b110

If you have both Python 3 and Python 2 installed, you can specify which version of Python you would like pip to use. This is useful when packages only support Python 2 or 3 or when you wish to test with both. If you want to install packages for Python 2, run either: pip install [package] or: p...