Tutorial by Examples: r

Create an instance of UIScrollView with a CGRect as frame. Swift let scrollview = UIScrollView.init(frame: CGRect(x: 0, y: 0, width: 320, height: 400)) Objective-C UIScrollView *scrollview = [[UIScrollView alloc] initWithFrame:CGRectMake(0, 0, 320, 400)];

The contentSize property must be set to the size of the scrollable content. This specifies the size of the scrollable area. Scrolling is visible when scrollable area i.e. contentSize is larger than the UIScrollView frame size. With Autolayout: When the scroll view's content is set up using autolay...

When referring to a worksheet, a range or individual cells, it is important to fully qualify the reference. For example: ThisWorkbook.Worksheets("Sheet1").Range(Cells(1, 2), Cells(2, 3)).Copy Is not fully qualified: The Cells references do not have a workbook and worksheet associated ...

C# allows user-defined types to control assignment and casting through the use of the explicit and implicit keywords. The signature of the method takes the form: public static <implicit/explicit> operator <ResultingType>(<SourceType> myType) The method cannot take any more argu...

Turn on: adb shell svc wifi enable Turn off: adb shell svc wifi disable

Start ADB: adb kill-server Stop ADB: adb start-server

To generate random permutation of 5 numbers: sample(5) # [1] 4 5 3 1 2 To generate random permutation of any vector: sample(10:15) # [1] 11 15 12 10 14 13 One could also use the package pracma randperm(a, k) # Generates one random permutation of k of the elements a, if a is a vector, # ...

'if only one area (not multiple areas): With Range("A3:D20") Debug.Print .Cells(.Cells.CountLarge).Row Debug.Print .Item(.Cells.CountLarge).Row 'using .item is also possible End With 'Debug prints: 20 'with multiple areas (also works if only one area): Dim rngArea As Range,...

Many developers like to customize the font, text, and background color of their IDE's. You can do this in Xcode by opening the app preference pane, either by going to XCODE->Preferences, or by pressing '⌘,' With the preference pane open you can click on the 'Fonts and Colors' tab. From her...

In Python 3.x all classes are new-style classes; when defining a new class python implicitly makes it inherit from object. As such, specifying object in a class definition is a completely optional: Python 3.x3.0 class X: pass class Y(object): pass Both of these classes now contain object in ...

Here is an example of a method that would live inside a SQLiteOpenHelper subclass. It uses the searchTerm String to filter the results, iterates through the Cursor's contents, and returns those contents in a List of Product Objects. First, define the Product POJO class that will be the container f...

Arrays You can iterate over nested arrays: [[1, 2], [3, 4]].each { |(a, b)| p "a: #{ a }", "b: #{ b }" } The following syntax is allowed too: [[1, 2], [3, 4]].each { |a, b| "a: #{ a }", "b: #{ b }" } Will produce: "a: 1" "b: 2" ...

CSS can be applied in multiple places: inline (Node.setStyle) in a stylesheet to a Scene as user agent stylesheet (not demonstrated here) as "normal" stylesheet for the Scene to a Node This allows to change styleable properties of Nodes. The following example demonst...

Equivalently, we can use the $inject property annotation to achieve the same as above: var MyController = function($scope) { // ... } MyController.$inject = ['$scope']; myModule.controller('MyController', MyController);

To start with multi-threading, you would need the pthreads-ext for php, which can be installed by $ pecl install pthreads and adding the entry to php.ini. A simple example: <?php // NOTE: Code uses PHP7 semantics. class MyThread extends Thread { /** * @var string * Variab...

Any class can configure its own string formatting syntax through the __format__ method. A type in the standard Python library that makes handy use of this is the datetime type, where one can use strftime-like formatting codes directly within str.format: >>> from datetime import datetime &...

Ansible can be installed on CentOS or other Red Hat based systems. Firstly you should install the prerequisites: sudo yum -y update sudo yum -y install gcc libffi-devel openssl-devel python-pip python-devel then install Ansible with pip: sudo pip install ansible I can recommend for you to u...

.' is the correct way to transpose a vector or matrix in MATLAB. ' is the correct way to take the complex conjugate transpose (a.k.a. Hermitian conjugate) of a vector or matrix in MATLAB. Note that for the transpose .', there is a period in front of the apostrophe. This is in keeping with the ...

WITH CTE (StudentId, Fname, LName, DOB, RowCnt) as ( SELECT StudentId, FirstName, LastName, DateOfBirth as DOB, SUM(1) OVER (Partition By FirstName, LastName, DateOfBirth) as RowCnt FROM tblStudent ) SELECT * from CTE where RowCnt > 1 ORDER BY DOB, LName This example uses a Common Table ...

Match any: Must match at least one string. In this example the product type must be either 'electronics', 'books', or 'video'. SELECT * FROM purchase_table WHERE product_type LIKE ANY ('electronics', 'books', 'video'); Match all (must meet all requirements). In this example both 'united...