Tutorial by Topics: as

A Hash is a dictionary-like collection of unique keys and their values. Also called associative arrays, they are similar to Arrays, but where an Array uses integers as its index, a Hash allows you to use any object type. You retrieve or create a new entry in a Hash by referring to its key. ...

VersionRelease Date0.991989-06-081.011989-06-232.01996-12-312.021998-04-202.031999-02-192.042001-03-212.05b2002-07-173.02004-08-033.12005-12-083.22006-10-114.02009-02-204.12009-12-314.22011-02-134.32014-02-264.42016-09-15

Visual Basic .NET is the official successor to Microsoft's original Visual Basic programming language. Visual Basic [.NET] appears to have similarities to Python with the lack of semicolons and brackets, but shares with C++ the basic structure of functions. Curly braces are absent in VB .NET, but ...

git rebase [-i | --interactive] [options] [--exec <cmd>] [--onto <newbase>] [<upstream>] [<branch>] git rebase [-i | --interactive] [options] [--exec <cmd>] [--onto <newbase>] --root [<branch>] git rebase --continue | --skip | --abort | --edit-todo ...

Shell aliases are a simple way to create new commands or to wrap existing commands with code of your own. They somewhat overlap with shell functions, which are however more versatile and should therefore often be preferred. The alias will only be available in the shell where the alias command...

assert expression1; assert expression1 : expression2; ParameterDetailsexpression1The assertion statement throws an AssertionError if this expression evaluates to false.expression2Optional. When used, AssertionErrors thrown by the assert statement have this message. By default, assertions ...

Python offers itself not only as a popular scripting language, but also supports the object-oriented programming paradigm. Classes describe data and provide methods to manipulate that data, all encompassed under a single object. Furthermore, classes allow for abstraction by separating concrete imple...

CSS specificity intends to promote code conciseness by allowing an author to define some general formatting rules for a broad set of elements, and then to override them for a certain subset.

The CASE expression is used to implement if-then logic. CASE input_expression  WHEN compare1 THEN result1 [WHEN compare2 THEN result2]... [ELSE resultX] END CASE  WHEN condition1 THEN result1 [WHEN condition2 THEN result2]... [ELSE resultX] END The simple CASE expression return...

The init() is a special method in classes which is used to declare an initializer for the class. More information can be found here: Initializers

Proc.new(block) lambda { |args| code } ->(arg1, arg2) { code } object.to_proc { |single_arg| code } do |arg, (key, value)| code end Be careful about operator precedence when you have a line with multiple methods chained, like: str = "abcdefg" puts str.gsub(/./) do |mat...

The $ character introduces parameter expansion, command substitution, or arithmetic expansion. The parameter name or symbol to be expanded may be enclosed in braces, which are optional but serve to protect the variable to be expanded from characters immediately following it which could be interprete...

Classes and Objects are used to to make your code more efficient and less repetitive by grouping similar tasks. A class is used to define the actions and data structure used to build objects. The objects are then built using this predefined structure. class <ClassName> [ extends <Par...

variable.member_var = constant; variable.member_function(); variable_pointer->member_var = constant; variable_pointer->member_function(); Note that the only difference between the struct and class keywords is that by default, the member variables, member functions, and base classe...

As more secure web services avoid storing passwords in plain text format, languages such as PHP provide various (undecryptable) hash functions to support the more secure industry standard. This topic provides documentation for proper hashing with PHP. string password_hash ( string $password , ...

An assertion is a predicate that the presented condition must be true at the moment the assertion is encountered by the software. Most common are simple assertions, which are validated at execution time. However, static assertions are checked at compile time. assert(expression) static_assert(...

Oracle is a relational database management system (RDBMS) originally built by Larry Ellison, Bob Miner, and Ed Oates in the late 70s. It was intended to be compatible with IBM's System R. VersionRelease DateVersion 1 (unreleased)1978-01-01Oracle V21979-01-01Oracle Version 31983-01-01Oracle Ver...