Tutorial by Examples: g

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() {} }

The keyword 'using' has three flavors. Combined with keyword 'namespace' you write a 'using directive': If you don't want to write Foo:: in front of every stuff in the namespace Foo, you can use using namespace Foo; to import every single thing out of Foo. namespace Foo { void bar() {} ...

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 ...

When creating a file stream, you can specify an opening mode. An opening mode is basically a setting to control how the stream opens the file. (All modes can be found in the std::ios namespace.) An opening mode can be provided as second parameter to the constructor of a file stream or to its open(...

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...

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...

The srcdoc attribute can be used (instead of the src attribute) to specify the exact contents of the iframe as a whole HTML document. This will yield an IFrame with the text "IFrames are cool!" <iframe srcdoc="<p>IFrames are cool!</p>"></iframe> If the...

When a user subscribes to a channel, you may want to set state for that newly subscribed user. While there is a subscribe with state API, there are some scenarios where this is not the most optimal/reliable technique (like during a disconnect/reconnect situation - the state will be lost and not rein...

To remove an element inside an array, e.g. the element with the index 1. $fruit = array("bananas", "apples", "peaches"); unset($fruit[1]); This will remove the apples from the list, but notice that unset does not change the indexes of the remaining elements. So $fr...

A cookie is set using the setcookie() function. Since cookies are part of the HTTP header, you must set any cookies before sending any output to the browser. Example: setcookie("user", "Tom", time() + 86400, "/"); // check syntax for function params Description: ...

Retrieve and Output a Cookie Named user The value of a cookie can be retrieved using the global variable $_COOKIE. example if we have a cookie named user we can retrieve it like this echo $_COOKIE['user'];

The value of a cookie can be modified by resetting the cookie setcookie("user", "John", time() + 86400, "/"); // assuming there is a "user" cookie already Cookies are part of the HTTP header, so setcookie() must be called before any output is sent to the...