Tutorial by Examples: pre

When an object is exposed to the template context, its arguments-less methods are available. This is useful when these functions are "getters". But it can be hazardeous if these methods alter some data or have some side effects. Eventhough you likely trust the template writer, he may not b...

Pre-processing in caret is done through the preProcess() function. Given a matrix or data frame type object x, preProcess() applies transformations on the training data which can then be applied to testing data. The heart of the preProcess() function is the method argument. Method operations are ap...

It is unlikely for a developer to not come across a deprecated API during a development process. A deprecated program element is one that programmers are discouraged from using, typically because it is dangerous, or because a better alternative exists. Compilers and analyzers (like LINT) warn when a...

Consider the following naive method for adding two positive numbers using recursion: public static int add(int a, int b) { if (a == 0) { return b; } else { return add(a - 1, b + 1); // TAIL CALL } } This is algorithmically correct, but it has a major problem. ...

Check screencast video on YouTube about this feature IntelliJ provides a quick-preview feature called Viewing Definition. Using this feature allows a user to quickly see the contents of a method/class without navigating into the class itself OS X - (⌘+Y) or (⌥+Space) Unix / Windows - Ctrl+Shif...

The most common conditional in Julia is the if...else expression. For instance, below we implement the Euclidean algorithm for computing the greatest common divisor, using a conditional to handle the base case: mygcd(a, b) = if a == 0 abs(b) else mygcd(b % a, a) end The if...else for...

$string = "a;b;c\nd;e;f"; // $1, $2 and $3 represent the first, second and third capturing groups echo preg_replace("(^([^;]+);([^;]+);([^;]+)$)m", "$3;$2;$1", $string); Outputs c;b;a f;e;d Searches for everything between semicolons and reverses the order.

When a function doesn't preserve units automatically due to lower-level operations, the LanguagePrimitives module can be used to set units on the primitives that support them: /// This cast preserves units, while changing the underlying type let inline castDoubleToSingle (x : float<'u>) : fl...

UITextView has extra paddings by default. Sometimes it's annoying especially if you want to measure some text without view instance and place them at some area precisely. Do this to remove such paddings. messageTextView.textContainerInset = UIEdgeInsetsZero messageTextView.textContainer.lineFragm...

Sometimes you would like to change main WordPress query. Filter pre_get_posts is the way to go. For example using pre_get_posts you can tell main loop to show only 5 posts. Or to show posts only from one category, or excluding any category etc. add_action( 'pre_get_posts', 'my_callback_function' ...

When the first time view is requested, normally Angular makes XHR request to get that view. For mid-size projects, the view count can be significant and it can slow down the application responsiveness. The good practice is to pre-load all the views at once for small and mid size projects. For large...

root: build.gradle buildscript { repositories { jcenter() } dependencies { classpath 'com.android.tools.build:gradle-experimental:0.8.0-alpha4' } } allprojects { repositories { jcenter() } } app: build.gradle apply plugin: 'com.andro...

Create this class : public class InputFilterMinMax implements InputFilter { private int min, max; public InputFilterMinMax(int min, int max) { this.min = min; this.max = max; } public InputFilterMinMax(String min, String max) { this.min = Integer...

Espresso by default has many matchers that help you find views that you need to do some checks or interactions with them. Most important ones can be found in the following cheat sheet: https://google.github.io/android-testing-support-library/docs/espresso/cheatsheet/ Some examples of matchers are...

Activity class takes care of creating a window for you in which you can place your UI with setContentView. There are three setContentView methods: setContentView(int layoutResID) - Set the activity content from a layout resource. setContentView(View view) - Set the activity content to an explic...

npm --install express-generator -g

/** * we reuse a class written in example: * http://stackoverflow.com/documentation/sockets/2876/introduction-to-sockets#t=201607262114505531351 * pleas to familiar with it first to continue with this one **/ public class WriteToSocketExample extends ConnectSocketExample { private ...

In GSP the <%= %> syntax is rarely used due to the support for GSP expressions. A GSP expression is similar to a JSP EL expression or a Groovy GString and takes the form ${expr}: <html> <body> Hello ${params.name} </body> </html> However, unlike JSP EL ...

There are several to evaluate a certain expression when debugging a Java application. 1. Manually inspecting an expression When the program execution is suspended at a certain line (either due to a breakpoint or manually stepping through the debugger), you can manually evaluate an expression by se...

The standard requires that long double provides at least as much precision as double, which provides at least as much precision as float; and that a long double can represent any value that a double can represent, while a double can represent any value that a float can represent. The details of the ...