Tutorial by Examples: d

You are not the only person working on the project, right? This means that your colleagues are also making modifications to the project's data. To stay up to date and to fetch the modifications committed by others, you should run svn update command in your working copy. As a result, your working cop...

A a pointer to a piece of memory containing n elements may only be dereferenced if it is in the range memory and memory + (n - 1). Dereferencing a pointer outside of that range results in undefined behavior. As an example, consider the following code: int array[3]; int *beyond_array = array + 3; ...

To delete a remote branch in Git: git push [remote-name] --delete [branch-name] or git push [remote-name] :[branch-name]

If a remote branch has been deleted, your local repository has to be told to prune the reference to it. To prune deleted branches from a specific remote: git fetch [remote-name] --prune To prune deleted branches from all remotes: git fetch --all --prune

Requirements: OS X 10.8 “Mountain Lion” or newer required to run Docker. While the docker binary can run natively on Mac OS X, to build and host containers you need to run a Linux virtual machine on the box. 1.12.0 Since version 1.12 you don't need to have a separate VM to be installed, as Docker...

Since Groups are "numbered" some engines also support matching what a group has previously matched again. Assuming you wanted to match something where two equals strings of length three are divided by a $ you'd use: (.{3})\$\1 This would match any of the following strings: "abc$...

Deleting the last element: std::vector<int> v{ 1, 2, 3 }; v.pop_back(); // v becomes {1, 2} Deleting all elements: std::vector<int> v{ 1, 2, 3 }; v.clear(); // v becomes an empty vector Deleting element by index: std::vect...

Evaluates its first operand, and, if the resulting value is not equal to zero, evaluates its second operand. Otherwise, it evaluates its third operand, as shown in the following example: a = b ? c : d; is equivalent to: if (b) a = c; else a = d; This pseudo-code represents it : c...

This example uses the Car Table from the Example Databases. SELECT * FROM Cars WHERE TotalCost IN (100, 200, 300) This query will return Car #2 which costs 200 and Car #3 which costs 100. Note that this is equivalent to using multiple clauses with OR, e.g.: SELECT * FROM Cars WHERE TotalCos...

See full documentation on LIKE operator. This example uses the Employees Table from the Example Databases. SELECT * FROM Employees WHERE FName LIKE 'John' This query will only return Employee #1 whose first name matches 'John' exactly. SELECT * FROM Employees WHERE FName like 'John%' Ad...

A simple application showing the text "Hello World" in the center of the window. import QtQuick 2.3 import QtQuick.Window 2.0 Window { visible: true width: 640 height: 480 title: qsTr("Hello World") //The method qsTr() is used for translations from one la...

In standard pattern matching, the identifier used will shadow any identifier in the enclosing scope. Sometimes it is necessary to match on the enclosing scope's variable. The following example function takes a character and a list of tuples and returns a new list of tuples. If the character existed...

The lambda keyword creates an inline function that contains a single expression. The value of this expression is what the function returns when invoked. Consider the function: def greeting(): return "Hello" which, when called as: print(greeting()) prints: Hello This can ...

This example shows the usage of the ILGenerator by generating code that makes use of already existing and new created members as well as basic Exception handling. The following code emits a DynamicAssembly that contains an equivalent to this c# code: public static class UnixTimeHelper { priva...

Branching in Subversion is very simple. In the simplest form, creating a new branch requires you to run the command against the remote repository's URLs. For example, let's create a new branch out of the mainline trunk: svn copy https://svn.example.com/svn/MyRepo/MyProject/trunk https://svn.example...

Delete a file asynchronously: var fs = require('fs'); fs.unlink('/path/to/file.txt', function(err) { if (err) throw err; console.log('file deleted'); }); You can also delete it synchronously*: var fs = require('fs'); fs.unlinkSync('/path/to/file.txt'); console.log('file deleted'...

This shows how you can iterate over multiple variables: for { x <- 1 to 2 y <- 'a' to 'd' } println("(" + x + "," + y + ")") (Note that to here is an infix operator method that returns an inclusive range. See the definition here.) This creates the outp...

Consider this simple project with a flat directory structure: example |-- example.asd |-- functions.lisp |-- main.lisp |-- packages.lisp `-- tools.lisp The example.asd file is really just another Lisp file with little more than an ASDF-specific function call. Assuming your project depends o...

The background-image property is used to specify a background image to be applied to all matched elements. By default, this image is tiled to cover the entire element, excluding margin. .myClass { background-image: url('/path/to/image.jpg'); } To use multiple images as background-image, defi...

Method Chaining is a technique explained in Martin Fowler's book Domain Specific Languages. Method Chaining is summarized as Makes modifier methods return the host object, so that multiple modifiers can be invoked in a single expression. Consider this non-chaining/regular piece of code (ported...