Tutorial by Examples: t

Modern A weak reference looks like one of these: @property (weak) NSString *property; NSString *__weak variable; If you have a weak reference to an object, then under the hood: You're not retaining it. When it gets deallocated, every reference to it will automatically be set to nil Obje...

This is an example of a program written with manual memory management. You really shouldn't write your code like this, unless for some reason you can't use ARC (like if you need to support 32-bit). The example avoids @property notation to illustrate how you used to have to write getters and setters....

Register a production/sandbox account at https://dashboard.stripe.com/register Insert below code into your webpage where you want to have a checkout button. <form action="/charge" method="POST"> <script src="https://checkout.stripe.com/checkout.js" cl...

A word of caution: AsyncTask has many gotcha's apart from the memory leak described here. So be careful with this API, or avoid it altogether if you don't fully understand the implications. There are many alternatives (Thread, EventBus, RxAndroid, etc). One common mistake with AsyncTask is to c...

The installation instructions are available on IIS.net. See this for installing IIS 8.5

when the object is saved/updated, check the associations and save/update any object that require it (including save/update the associations in many-to-many scenario).

when the object is deleted, delete all the objects in the association.

when the object is deleted, delete all the objects in the association. In addition to that, when an object is removed from the association and not associated with another object (orphaned), also delete it.

when an object is save/update/delete, check the associations and save/update/delete all the objects found. In additional to that, when an object is removed from the association and not associated with another object (orphaned), also delete it.

Send an HTTP response with status code 200 to indicate a successful request. The HTTP response status line is then: HTTP/1.1 200 OK The status text OK is only informative. The response body (message payload) should contain a representation of the requested resource. If there is no representation...

Assuming that you have successfully created a JFrame and that Swing has been imported... You can import Swing entirely import javax.Swing.*; or You can import the Swing Components/Frame that you intend to use import javax.Swing.Jframe; import javax.Swing.JButton; Now down to adding the J...

Leaflet is an open-source JavaScript library for making dynamic maps for the web. RStudio wrote R bindings for Leaflet, available through its leaflet package, built with htmlwidgets. Leaflet maps integrate well with the RMarkdown and Shiny ecosystems. The interface is piped, using a leaflet() funct...

PHP is a loosely typed language. This means that, by default, it doesn't require operands in an expression to be of the same (or compatible) types. For example, you can append a number to a string and expect it to work. var_dump ("This is example number " . 1); The output will be: ...

Switch statements use non-strict comparison to determine matches. This can lead to some nasty surprises. For example, consider the following statement: switch ($name) { case 'input 1': $mode = 'output_1'; break; case 'input 2': $mode = 'output_2'; bre...

When you install Oracle 11g or 12cR1, an older version of Apex is pre-installed. It is highly recommended to upgrade it to the latest version. Go to apex.oracle.com and download the latest version of Apex. Follow the documentation for the specific version to install it. Important Docu...

Add the following dependency to the build.gradle file: compile 'com.nostra13.universalimageloader:universal-image-loader:1.9.5' Add the following permissions to the AndroidManifest.xml file: <uses-permission android:name="android.permission.INTERNET" /> <uses-permiss...

A very useful and logical follow-up to histograms would be to plot the smoothed density function of a random variable. A basic plot produced by the command plot(density(rnorm(100)),main="Normal density",xlab="x") would look like You can overlay a histogram and a density...

To change MySQL's root user password: Step 1: Stop the MySQL server. in Ubuntu or Debian: sudo /etc/init.d/mysql stop in CentOS, Fedora or Red Hat Enterprise Linux: sudo /etc/init.d/mysqld stop Step 2: Start the MySQL server without the privilege system. sudo mysqld_safe --skip-grant-tab...

strsplit is a useful function for breaking up a vector into an list on some character pattern. With typical R tools, the whole list can be reincorporated to a data.frame or part of the list might be used in a graphing exercise. Here is a common usage of strsplit: break a character vector along a co...

Haskell has list comprehensions, which are a lot like set comprehensions in math and similar implementations in imperative languages such as Python and JavaScript. At their most basic, list comprehensions take the following form. [ x | x <- someList ] For example [ x | x <- [1..4] ] -...