Tutorial by Examples: in

Multiple Inheritance

Aside from single inheritance: class A {}; class B : public A {}; You can also have multiple inheritance: class A {}; class B {}; class C : public A, public B {}; C will now have inherit from A and B at the same time. Note: this can lead to ambiguity if the same names are used in multipl...

C++ • Classes/Structures

Sharing ownership (std::shared_ptr)

The class template std::shared_ptr defines a shared pointer that is able to share ownership of an object with other shared pointers. This contrasts to std::unique_ptr which represents exclusive ownership. The sharing behavior is implemented through a technique known as reference counting, where the...

C++ • Smart Pointers

Sharing with temporary ownership (std::weak_ptr)

Instances of std::weak_ptr can point to objects owned by instances of std::shared_ptr while only becoming temporary owners themselves. This means that weak pointers do not alter the object's reference count and therefore do not prevent an object's deletion if all of the object's shared pointers are ...

C++ • Smart Pointers

What is Function Overloading?

Function overloading is having multiple functions declared in the same scope with the exact same name exist in the same place (known as scope) differing only in their signature, meaning the arguments they accept. Suppose you are writing a series of functions for generalized printing capabilities, b...

C++ • Function Overloading

Initializing a std::vector

A std::vector can be initialized in several ways while declaring it: C++11 std::vector<int> v{ 1, 2, 3 }; // v becomes {1, 2, 3} // Different from std::vector<int> v(3, 6) std::vector<int> v{ 3, 6 }; // v becomes {3, 6} // Different from std::vector<int> v{3, ...

C++ • std::vector

Inserting Elements

Appending an element at the end of a vector (by copying/moving): struct Point { double x, y; Point(double x, double y) : x(x), y(y) {} }; std::vector<Point> v; Point p(10.0, 2.0); v.push_back(p); // p is copied into the vector. C++11 Appending an element at the end of a vector ...

C++ • std::vector

Iterating Over std::vector

You can iterate over a std::vector in several ways. For each of the following sections, v is defined as follows: std::vector<int> v; Iterating in the Forward Direction C++11 // Range based for for(const auto& value: v) { std::cout << value << "\n"; } /...

C++ • std::vector

Accessing Elements

There are two primary ways of accessing elements in a std::vector index-based access iterators Index-based access: This can be done either with the subscript operator [], or the member function at(). Both return a reference to the element at the respective position in the std::vector (unles...

C++ • std::vector

Using std::vector as a C array

There are several ways to use a std::vector as a C array (for example, for compatibility with C libraries). This is possible because the elements in a vector are stored contiguously. C++11 std::vector<int> v{ 1, 2, 3 }; int* p = v.data(); In contrast to solutions based on previous C++ st...

C++ • std::vector

Creating DOM elements

The jQuery function (usually aliased as $) can be used both to select elements and to create new elements. var myLink = $('<a href="http://stackexchange.com"></a>'); You can optionally pass a second argument with element attributes: var myLink = $('<a>', { 'href': 'h...

jQuery • DOM Manipulation

Manipulating element classes

Assuming the page includes an HTML element like: <p class="small-paragraph"> This is a small <a href="https://en.wikipedia.org/wiki/Paragraph">paragraph</a> with a <a class="trusted" href="http://stackexchange.com">link</a>...

jQuery • DOM Manipulation

Adding the jQuery UI script & basic usage

To get started with the jQuery UI library, you'll need to add the jQuery script, the jQuery UI script, and the jQuery UI stylesheet to your HTML. First, download jQuery UI; choose the features you need on the download page. Unzip your download, and put jquery-ui.css and jquery-ui.js (and jquery.js)...

jQuery UI Library • Getting started with jQuery UI Library

Selecting elements using CSS selectors

String html = "<!DOCTYPE html>" + "<html>" + "<head>" + "<title>Hello world!</title>" + "</head>" + "<body>" + ...

Jsoup • Selectors

Number of Lines

When you make a label and set its text to be more than a single line that it can display, it will be truncated and you will see only one line of text ending with three dots (...). This is because a property called numberOfLines is set to 1, and therefore only one line will be displayed. It is a comm...

iOS • UILabel

Creating a UIButton

UIButtons can be initialized in a frame: Swift let button = UIButton(frame: CGRect(x: x, y: y, width: width, height: height) Objective C UIButton *button = [[UIButton alloc] initWithFrame:CGRectMake(x, y, width, height)]; A specific type of UIButton can be created like this: Swift let but...

iOS • UIButton

Horizontally aligning contents

Swift //Align contents to the left of the frame button.contentHorizontalAlignment = .left //Align contents to the right of the frame button.contentHorizontalAlignment = .right //Align contents to the center of the frame button.contentHorizontalAlignment = .center //Make contents fill th...

iOS • UIButton

Getting the title label

The underlying title label, if one exists, can be fetched using Swift var label: UILabel? = button.titleLabel Objective C UILabel *label = button.titleLabel; This can be used to set the font of the title label, for example Swift button.titleLabel?.font = UIFont.boldSystemFontOfSize(12) ...

iOS • UIButton

Using the `HTTP[S]_PROXY` env var

This page describes how to use the Meteor command-line tool (for example, when downloading packages, deploying your app, etc) behind a proxy server. Like a lot of other command-line software, the Meteor tool reads the proxy configuration from the HTTP_PROXY and HTTPS_PROXY environment variables (th...

meteor • Using Meteor with a Proxy Server

Nil Coalescing Operator

You can use the nil coalescing operator to unwrap a value if it is non-nil, otherwise provide a different value: func fallbackIfNil(str: String?) -> String { return str ?? "Fallback String" } print(fallbackIfNil("Hi")) // Prints "Hi" print(fallbackIfNil(nil)...

Swift Language • Optionals

Using PuTTY (Advanced)

If you don't want to add Unix commands to your PATH on Windows, you can download a standalone SSH client like PuTTY. Download PuTTY here, then follow the instructions below to get a build machine. Call meteor admin get-machine <os-architecture> --json Copy and save the private key from the...

meteor • Accessing Meteor build machines from Windows