Tutorial by Examples: if

Files: To determine if a file exists, simply pass the filename to the Dir$ function and test to see if it returns a result. Note that Dir$ supports wild-cards, so to test for a specific file, the passed pathName should to be tested to ensure that it does not contain them. The sample below raises an...

You may need to render some content in view, which is specific to some environment only. To achieve this goal you can use Environment tag helper: <environment names="Development"> <h1>This is heading for development environment</h1> </environment> <envi...

Suppose you have a long list of elements and you are only interested in every other element of the list. Perhaps you only want to examine the first or last elements, or a specific range of entries in your list. Python has strong indexing built-in capabilities. Here are some examples of how to achie...

You can close a notification by using the .close() method. let notification = new Notification(title, options); // do some work, then close the notification notification.close() You can utilize the setTimeout function to auto-close the notification sometime in the future. let notification = n...

The Notification API specifications support 2 events that can be fired by a Notification. The click event. This event will run when you click on the notification body (excluding the closing X and the Notifications configuration button). Example: notification.onclick = function(event) { ...

The NotifyPropertyChangedBaseclass below defines a generic Set method that can be called from any derived type. public class NotifyPropertyChangedBase : INotifyPropertyChanged { protected void RaisePropertyChanged([CallerMemberName] string propertyName = null) => PropertyChanged?.Invo...

To prevent memory leaks, one should not forget to close an input stream or an output stream whose job is done. This is usually done with a try-catch-finally statement without the catch part: void writeNullBytesToAFile(int count, String filename) throws IOException { FileOutputStream out = null...

It is always a good practice to test how push notifications work even before you have your server side ready for them, just to make sure that everything is set up correctly on your side. It is quite easy to send yourself a push notification using a following PHP script. Save the script as a file ...

Save aps.cer to a folder Open "Keychain access" and export the key that is under that certificate to a .p12 file (call it key.p12). To do that right click on it and choose Export. Save it to the same folder as step 1. On export you will be prompted for a password. Make something u...

Swift 2.3 let url = NSURL(string: "http://google.com/lastPath") let lastPath = url?.lastPathComponent Swift 3.0 let url = URL(string: "http://google.com/lastPath") let lastPath = url?.lastPathComponent

Sometimes, the latest tagged version of a package is buggy or is missing some required features. Advanced users may wish to update to the latest development version of a package (sometimes referred to as the "master", named after the usual name for a development branch in Git). The benefit...

Julia Symbol literals must be legal identifiers. This works: julia> :cat :cat But this does not: julia> :2cat ERROR: MethodError: no method matching *(::Int64, ::Base.#cat) Closest candidates are: *(::Any, ::Any, ::Any, ::Any...) at operators.jl:288 *{T<:Union{Int128,Int16,Int...

Without replacement With combn, each vector appears in a column: combn(LETTERS, 3) # Showing only first 10. [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10] [1,] "A" "A" "A" "A" "A" "A" "A" "A" &quo...

Without replacement choose(length(LETTERS), 5) [1] 65780 With replacement length(letters)^5 [1] 11881376

Keys Unlike a Scripting.Dictionary, a Collection does not have a method for determining if a given key exists or a way to retrieve keys that are present in the Collection. The only method to determine if a key is present is to use the error handler: Public Function KeyExistsInCollection(ByVal key...

This uses the SwiftyDropbox library to upload a file from a NSFileHandle to the Dropbox account using upload sessions, handling every error case: import UIKit import SwiftyDropbox class ViewController: UIViewController { // filled in later in doUpload: var fileHandle : NSFileHandle?...

var express = require("express"), bodyParser = require("body-parser"), server = express(); //body parser for parsing request body server.use(bodyParser.json()); server.use(bodyParser.urlencoded({ extended: true })); //temperary store for `item` in memory var it...

You do not need to use double negation in if-else statements. if 'hello' puts 'hey!' else puts 'bye!' end The above code prints 'hey!' on the screen.

Accessing the array of calendars To access the array of EKCalendars, we use the calendarsForEntityType method: Swift let calendarsArray = eventStore.calendarsForEntityType(EKEntityType.Event) as! [EKCalendar] Iterating through calendars Just use a simple for loop: Swift for calendar in cale...

DECLARE v_num1 NUMBER(10); v_num2 NUMBER(10); BEGIN v_num1 := 2; v_num2 := 1; IF v_num1 > v_num2 THEN dbms_output.put_line('v_num1 is bigger than v_num2'); END IF; END;