Tutorial by Examples: f

Every function has its own function type, made up of the parameter types and the return type of the function itself. For example the following function: func sum(x: Int, y: Int) -> (result: Int) { return x + y } has a function type of: (Int, Int) -> (Int) Function types can thus be use...

Problem: When you use many labels inside a view, you maybe get a warning: How can we fix this warning? Solution: We calculate and set the priorities in order. The priorities must be different from labels. It means which is important will get higher priority. For example, in my case, I set the ve...

Often in R you'll want to know things about an object or variable you're working with. This can be useful when reading someone else's code or even your own, especially when using packages that are new to you. Suppose we create a variable a: a <- matrix(1:9, 3, 3) What data type is this? Yo...

The Oracle Java Style Guide states: Modifiers should not be written out when they are implicit. (See Modifiers in Oracle Official Code Standard for the context and a link to the actual Oracle document.) This style guidance applies particularly to interfaces. Let's consider the following code ...

In this exercise, we will generate four bootstrap linear regression models and combine the summaries of these models into a single data frame. library(broom) #* Create the bootstrap data sets BootData <- lapply(1:4, function(i) mtcars[sample(1:nrow(mtcars), ...

The degree of parallelism is the maximum number of concurrently executing tasks that will be used to process the query. var sequence = Enumerable.Range(1, 10000); var evenNumbers = sequence.AsParallel() .WithDegreeOfParallelism(4) .Where(x =&gt...

a, b = 1, 2 import math math.sin(a) # returns the sine of 'a' in radians # Out: 0.8414709848078965 math.cosh(b) # returns the inverse hyperbolic cosine of 'b' in radians # Out: 3.7621956910836314 math.atan(math.pi) # returns the arc tangent of 'pi' in radians # Out: 1.2626272556789...

A typical use case for SpriteKit is where the SKView fills the whole screen. To do this in Xcode's Interface Builder, first create a normal ViewController, then select the contained view and change its Class from UIView to SKView: Within the code for the View Controller, in the viewDidLoad metho...

fastlane is an open source build automation tool for Android and iOS for developers. It reduce your build generation time. It is a command line tool that uses Ruby, so you need Ruby on your computer. Most Macs already have Ruby installed by default. Install fastlane Open a terminal. Run sudo ge...

2 Dimensional arrays 6 In ES6, we can flatten the array by the spread operator ...: function flattenES6(arr) { return [].concat(...arr); } var arrL1 = [1, 2, [3, 4]]; console.log(flattenES6(arrL1)); // [1, 2, 3, 4] 5 In ES5, we can acheive that by .apply(): function flatten(arr) { ...

As Angular uses HTML to extend a web page and plain Javascript to add logic, it makes it easy to create a web page using ng-app, ng-controller and some built-in directives such as ng-if, ng-repeat, etc. With the new controllerAs syntax, newcomers to Angular users can attach functions and data to the...

Factors are one method to represent categorical variables in R. Given a vector x whose values can be converted to characters using as.character(), the default arguments for factor() and as.factor() assign an integer to each distinct element of the vector as well as a level attribute and a label attr...

public function drawDisplayObjectUsingBounds(source:DisplayObject):BitmapData { var bitmapData:BitmapData;//declare a BitmapData var bounds:Rectangle = source.getBounds(source);//get the source object actual size //round bounds to integer pixel values (to aviod 1px str...

One of the most common errors in compilation happens during the linking stage. The error looks similar to this: $ gcc undefined_reference.c /tmp/ccoXhwF0.o: In function `main': undefined_reference.c:(.text+0x15): undefined reference to `foo' collect2: error: ld returned 1 exit status $ So l...

Const baseString As String = "Hello World" Dim charLength As Long charLength = Len(baseString) 'charlength = 11

Const baseString As String = "Hello World" Dim byteLength As Long byteLength = LenB(baseString) 'byteLength = 22

When checking if a string is zero-length, it is better practice, and more efficient, to inspect the length of the string rather than comparing the string to an empty string. Const myString As String = vbNullString 'Prefer this method when checking if myString is a zero-length string If Len(mySt...

One common scenario is to wait for a number of requests to finish before continuing. This can be accomplished using the forkJoin method. In the following example, forkJoin is used to call two methods that return Observables. The callback specified in the .subscribe method will be called when both O...

ADO connections can be used to perform pretty much any database function that the provider supports via SQL. In this case it isn't always necessary to use the Recordset returned by the Execute function, although it can be useful for obtaining key assignments after INSERT statements with @@Identity o...

'Declare and assign a string array Dim widgetNames(2) As String widgetNames(0) = "foo" widgetNames(1) = "bar" widgetNames(2) = "fizz" 'Concatenate with Join and separate each element with a 3-character string concatenatedString = VBA.Strings.Join(widgetNames, &q...