Tutorial by Examples

Dim Value As Variant 'Explicit Dim Value 'Implicit A Variant is a COM data type that is used for storing and exchanging values of arbitrary types, and any other type in VBA can be assigned to a Variant. Variables declared without an explicit type specified by As [Type] default t...

Dim Value As LongPtr The LongPtr was introduced into VBA in order to support 64 bit platforms. On a 32 bit system, it is treated as a Long and on 64 bit systems it is treated as a LongLong. It's primary use is in providing a portable way to store and pass pointers on both architectures (See Chan...

To define a new middleware we have to create the middleware class: class AuthenticationMiddleware { //this method will execute when the middleware will be triggered public function handle ( $request, Closure $next ) { if ( ! Auth::user() ) { return red...

Callbacks can be used to provide code to be executed after a method has completed: /** * @arg {Function} then continuation callback */ function doSomething(then) { console.log('Doing something'); then(); } // Do something, then execute callback to log 'done' doSomething(function () ...

Callbacks are often used to provide error handling. This is a form of control flow branching, where some instructions are executed only when an error occurs: const expected = true; function compare(actual, success, failure) { if (actual === expected) { success(); } else { failure...

If you want to delete rows (or columns) in a loop, you should always loop starting from the end of range and move back in every step. In case of using the code: Dim i As Long With Workbooks("Book1").Worksheets("Sheet1") For i = 1 To 4 If IsEmpty(.Cells(i, 1)) Then...

#Modules to use use Cwd 'abs_path'; use Win32::OLE; use Win32::OLE qw(in with); use Win32::OLE::Const "Microsoft Excel"; $Win32::OLE::Warn = 3; #Need to use absolute path for Excel files my $excel_file = abs_path("$Excel_path") or die "Error: the file $Excel_path ha...

#Get the active Worksheet my $Book = $Excel->Activewindow; my $Sheet = $Book->Activesheet; #List of Worksheet names my @list_Sheet = map { $_->{'Name'} } (in $Book->{Worksheets}); #Access a given Worksheet my $Sheet = $Book->Worksheets($list_Sheet[0]); #Add new Worksheet...

#Edit the value of a cell (2 methods) $Sheet->Range("A1")->{Value} = 1234; $Sheet->Cells(1,1)->{Value} = 1234; #Edit the values in a range of cells $Sheet->Range("A8:C9")->{Value} = [[ undef, 'Xyzzy', 'Plugh' ], [ 42, 'Pe...

#Insert a row before/after line 22 $Sheet->Rows("22:22")->Insert(xlUp, xlFormatFromRightOrBelow); $Sheet->Rows("23:23")->Insert(-4121,0); #xlDown is -4121 and that xlFormatFromLeftOrAbove is 0 #Delete a row $Sheet->Rows("22:22")->Delete(); ...

In ui-router a state can hold multiple views, each with his own controller and a template .state('dashboard', { name: 'dashboard', url: '/dashboard', views: { "view1": { templateUrl: "path/to/view1.html", controller: "...

You can resolve data into your state when you transition into it, usually it's useful when the state needs to use that data, or to resolve into a state when some provided input needs to be authenticated. When you define your states, you will need to provide a map of values to be resolved into the ....

The syntax for filtering for NULL (i.e. the absence of a value) in WHERE blocks is slightly different than filtering for specific values. SELECT * FROM Employees WHERE ManagerId IS NULL ; SELECT * FROM Employees WHERE ManagerId IS NOT NULL ; Note that because NULL is not equal to anything, not ...

When creating tables it is possible to declare a column as nullable or non-nullable. CREATE TABLE MyTable ( MyCol1 INT NOT NULL, -- non-nullable MyCol2 INT NULL -- nullable ) ; By default every column (except those in primary key constraint) is nullable unless we explicitly set ...

Setting a field to NULL works exactly like with any other value: UPDATE Employees SET ManagerId = NULL WHERE Id = 4

For example inserting an employee with no phone number and no manager into the Employees example table: INSERT INTO Employees (Id, FName, LName, PhoneNumber, ManagerId, DepartmentId, Salary, HireDate) VALUES (5, 'Jane', 'Doe', NULL, NULL, 2, 800, '2016-07-22') ;

To customize appearance of all instances of a class, access appearance proxy of the desired class. For example: Set UIButton tint color Swift: UIButton.appearance().tintColor = UIColor.greenColor() Objective-C: [UIButton appearance].tintColor = [UIColor greenColor]; Set UIButton background...

Use appearanceWhenContainedInInstancesOfClasses: to customize the appearance for instance of a class when contained within an instance of container class. For example customization of UILabel's textColor and backgroundColor within ViewController class will look like this: Set UILabel text color Sw...

Not everyone agrees on what the most semantically correct method for resource creation is. Thus, your API could accept POST or PUT requests, or either. The server should respond with 201 Created if the resource was successfully created. Pick the most appropriate error code if it was not. For examp...

Editing or updating a resource is a common purpose for APIs. Edits can be achieved by sending either POST, PUT or PATCH requests to the respective resource. Although POST is allowed to append data to a resource's existing representation it is recommended to use either PUT or PATCH as they convey a m...