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In ECMAScript 6, when using the module syntax (import/export), each file becomes its own module with a private namespace. Top-level functions and variables do not pollute the global namespace. To expose functions, classes, and variables for other modules to import, you can use the export keyword. /...

Given that the module from the Defining a Module section exists in the file test.js, you can import from that module and use its exported members: import {doSomething, MyClass, PI} from './test' doSomething() const mine = new MyClass() mine.test() console.log(PI) The somethingPrivate()...

A C++ namespace is a collection of C++ entities (functions, classes, variables), whose names are prefixed by the name of the namespace. When writing code within a namespace, named entities belonging to that namespace need not be prefixed with the namespace name, but entities outside of it must use t...

Creating a namespace is really easy: //Creates namespace foo namespace Foo { //Declares function bar in namespace foo void bar() {} } To call bar, you have to specify the namespace first, followed by the scope resolution operator ::: Foo::bar(); It is allowed to create one names...

A useful feature of namespaces is that you can expand them (add members to it). namespace Foo { void bar() {} } //some other stuff namespace Foo { void bar2() {} }

Opening a file is done in the same way for all 3 file streams (ifstream, ofstream, and fstream). You can open the file directly in the constructor: std::ifstream ifs("foo.txt"); // ifstream: Opens file "foo.txt" for reading only. std::ofstream ofs("foo.txt"); // ...

There are several ways to read data from a file. If you know how the data is formatted, you can use the stream extraction operator (>>). Let's assume you have a file named foo.txt which contains the following data: John Doe 25 4 6 1987 Jane Doe 15 5 24 1976 Then you can use the following...

There are several ways to write to a file. The easiest way is to use an output file stream (ofstream) together with the stream insertion operator (<<): std::ofstream os("foo.txt"); if(os.is_open()){ os << "Hello World!"; } Instead of <<, you can also ...

Explicitly closing a file is rarely necessary in C++, as a file stream will automatically close its associated file in its destructor. However, you should try to limit the lifetime of a file stream object, so that it does not keep the file handle open longer than necessary. For example, this can be ...

In addition to importing named members from a module or a module's default export, you can also import all members into a namespace binding. import * as test from './test' test.doSomething() All exported members are now available on the test variable. Non-exported members are not available, j...

Sometimes you may encounter members that have really long member names, such as thisIsWayTooLongOfAName(). In this case, you can import the member and give it a shorter name to use in your current module: import {thisIsWayTooLongOfAName as shortName} from 'module' shortName() You can import m...

Common values from both sets: You can use the intersect(_:) method to create a new set containing all the values common to both sets. let favoriteColors: Set = ["Red", "Blue", "Green"] let newColors: Set = ["Purple", "Orange", "Green"] ...

To create a new branch, while staying on the current branch, use: git branch <name> Generally, the branch name must not contain spaces and is subject to other specifications listed here. To switch to an existing branch : git checkout <name> To create a new branch and switch to it...

Let's say you've got a list of restaurants -- maybe you read it from a file. You care about the unique restaurants in the list. The best way to get the unique elements from a list is to turn it into a set: restaurants = ["McDonald's", "Burger King", "McDonald's", &qu...

collections.defaultdict(default_factory) returns a subclass of dict that has a default value for missing keys. The argument should be a function that returns the default value when called with no arguments. If there is nothing passed, it defaults to None. >>> state_capitals = collections.d...

$ git branch -d dev Deletes the branch named dev if its changes are merged with another branch and will not be lost. If the dev branch does contain changes that have not yet been merged that would be lost, git branch -d will fail: $ git branch -d dev error: The branch 'dev' is not fully merged...

<input type="password" name="password"> The input element with a type attribute whose value is password creates a single-line text field similar to the input type=text, except that text is not displayed as the user enters it. <input type="password" name=&qu...

The term "IFrame" means Inline Frame. It can be used to include another page in your page. This will yield a small frame which shows the exact contents of the base.html. <iframe src="base.html"></iframe>

The IFrame can be resized using the width and height attributes, where the values are represented in pixels (HTML 4.01 allowed percentage values, but HTML 5 only allows values in CSS pixels). <iframe src="base.html" width="800" height="600"></iframe>

Normally a change of webpage within an Iframe is initiated from with the Iframe, for example, clicking a link inside the Ifame. However, it is possible to change an IFrame's content from outside the IFrame. You can use an anchor tag whose href attribute is set to the desired URL and whose target at...