Tutorial by Examples: u

Incorrect Code Sub DoSomething() GoSub DoThis DoThis: Debug.Print "Hi!" Return End Sub Why doesn't this work? Execution enters the DoSomething procedure, jumps to the DoThis label, prints "Hi!" to the debug output, returns to the instruction immediately afte...

Incorrect code Sub DoSomething() Dim row As Integer For row = 1 To 100000 'do stuff Next End Sub Why doesn't this work? The Integer data type is a 16-bit signed integer with a maximum value of 32,767; assigning it to anything larger than that will overflow the type and ...

Incorrect code Sub DoSomething() Dim foo(1 To 10) Dim i As Long For i = 1 To 100 foo(i) = i Next End Sub Why doesn't this work? foo is an array that contains 10 items. When the i loop counter reaches a value of 11, foo(i) is out of range. This error occurs whenever...

Incorrect code Public Sub DoSomething() DoSomethingElse "42?" End Sub Private Sub DoSomethingElse(foo As Date) ' Debug.Print MonthName(Month(foo)) End Sub Why doesn't this work? VBA is trying really hard to convert the "42?" argument into a Date value. When it ...

Incorrect code Sub DoSomething() Dim foo As Collection With foo .Add "ABC" .Add "XYZ" End With End Sub Why doesn't this work? Object variables hold a reference, and references need to be set using the Set keyword. This error occurs whenever ...

you can set a Jekyll environment and value, when build time JEKYLL_ENV=production jekyll b JEKYLL_ENV=production jekyll build JEKYLL_ENV=production bundle exec jekyll build if your code contains the bellow snippet, analytics.html will not be included unless your building with JEKYLL_ENV=...

The following code illustrates how to do simple popup with Kivy. from kivy.app import App from kivy.uix.popup import Popup from kivy.lang import Builder from kivy.uix.button import Button Builder.load_string(''' <SimpleButton>: on_press: self.fire_popup() <SimplePopup>: ...

To create a Java lambda using the GUI, first make sure you have your distribution zip ready. You will also need an AWS account that can create lambdas. Switch to the AWS Lambda, dismiss the introduction screen (or read the Get Started documentation) and press the button Create a Lambda Function. ...

@Grab(group='org.codehaus.groovy.modules.http-builder', module='http-builder', version='0.7' ) import groovyx.net.http.RESTClient try { def restClient = new RESTClient("http://weathers.co") def response = restClient.get(path: '/api.php', query: ['city': 'Prague']) prin...

The known sub-classes for Entity Events are: Sub-ClassesSub-ClassesSub-ClassesCreatureSpawnEventCreeperPowerEventEntityChangeBlockEventEntityCombustEventEntityCreatePortalEventEntityDamageEventEntityDeathEventEntityExplodeEventEntityInteractEventEntityPortalEnterEventEntityRegainHealthEventEntitySh...

UITabBarController building in Swift 3 Change image color and title according to selection with changing selected tab color. import UIKit class TabbarController: UITabBarController { override func viewDidLoad() { super.viewDidLoad() self.navigationController?.isNavigat...

Type Casting Type casting is a way to check the type of an instance, or to treat that instance as a different superclass or subclass from somewhere else in its own class hierarchy. Type casting in Swift is implemented with the is and as operators. These two operators provide a simple and express...

Here is a Rules example in Rules export format: { "rules_display_userpoints_after_updating_content" : { "LABEL" : "Display userpoints after updating content", "PLUGIN" : "reaction rule", "OWNER" : "rules", &qu...

Let's create a small piece of code that throws an exception: private void button1_Click(object sender, EventArgs e) { string msg = null; msg.ToCharArray(); } If we execute this, we get the following Exception and stack trace: System.NullReferenceException: "Object reference not...

Detailed instructions on getting django-forms set up or installed.

Flexbox is a CSS3 module, standardized by the World Wide Web Consortium. It is a layout mode for element arrangement such that the elements behave predictably when the page layout must accommodate different display sizes. Because it is a part of CSS3, you don't need to install anything. It can be u...

Django Model Form with Django Class Based view is a classic way of building pages to do create/update operations in django application quickly. Within the form we can put methods to execute tasks. Its a cleaner way to put tasks in forms rather than putting in views/models. To give an example using ...

Incorrect code Sub DoSomething() On Error GoTo CleanFail DoSomethingElse CleanFail: Debug.Print Err.Number Resume Next End Sub Why doesn't this work? If the DoSomethingElse procedure raises an error, execution jumps to the CleanFail line label, prints the error number, a...

Built-in forms are great but sometimes there is a need to customize them, adding new fields or simply changing CSS attributes. This example is applicable to several use cases but here it is presented regarding PasswordChangeForm and its use in a Bootstrap website. The solution is to create another...