Tutorial by Examples: f

Given a Person struct struct Person { let name: String let birthYear: Int? } and an Array of Person(s) let persons = [ Person(name: "Walter White", birthYear: 1959), Person(name: "Jesse Pinkman", birthYear: 1984), Person(name: "Skyler White&quo...

Custom Renderers let developers customize the appearance and behavior of Xamarin.Forms controls on each platform. Developers could use features of native controls. For example, we need to disable scroll in ListView. On iOS ListView is scrollable even if all items are placed on the screen and user s...

Retrofit2 comes with support for multiple pluggable execution mechanisms, one of them is RxJava. To use retrofit with RxJava you first need to add the Retrofit RxJava adapter to your project: compile 'com.squareup.retrofit2:adapter-rxjava:2.1.0' then you need to add the adapter when building yo...

C++11 introduced core language and standard library support for moving an object. The idea is that when an object o is a temporary and one wants a logical copy, then its safe to just pilfer o's resources, such as a dynamically allocated buffer, leaving o logically empty but still destructible and co...

Placeholders allow you to feed values into a tensorflow graph. Aditionally They allow you to specify constraints regarding the dimensions and data type of the values being fed in. As such they are useful when creating a neural network to feed new training examples. The following example declares a ...

Type synonym families are just type-level functions: they associate parameter types with result types. These come in three different varieties. Closed type-synonym families These work much like ordinary value-level Haskell functions: you specify some clauses, mapping certain types to others: {-# ...

Data families can be used to build datatypes that have different implementations based on their type arguments. Standalone data families {-# LANGUAGE TypeFamilies #-} data family List a data instance List Char = Nil | Cons Char (List Char) data instance List () = UnitList Int In the above de...

The intent attribute of a dummy argument in a subroutine or function declares its intended use. The syntax is either one of intent(IN) intent(OUT) intent(INOUT) For example, consider this function: real function f(x) real, intent(IN) :: x f = x*x end function The intent(IN) specif...

You can use the if binding to determine whether or not the child elements of the node should be created. <div class="product-info"> <h2> Product1 </h2> <img src="../products/product1.jpg"/> <span data-bind="if:featured"> ...

Types of columns can be checked by .dtypes atrribute of DataFrames. In [1]: df = pd.DataFrame({'A': [1, 2, 3], 'B': [1.0, 2.0, 3.0], 'C': [True, False, True]}) In [2]: df Out[2]: A B C 0 1 1.0 True 1 2 2.0 False 2 3 3.0 True In [3]: df.dtypes Out[3]: A int64 ...

This example shows how to create a prepared statement with an insert statement with parameters, set values to those parameters and then executing the statement. Connection connection = ... // connection created earlier try (PreparedStatement insert = connection.prepareStatement( "i...

In PaaS sites such as Heroku, it is usual to receive the database information as a single URL environment variable, instead of several parameters (host, port, user, password...). There is a module, dj_database_url which automatically extracts the DATABASE_URL environment variable to a Python dictio...

When you create a function in TypeScript you can specify the data type of the function's arguments and the data type for the return value Example: function sum(x: number, y: number): number { return x + y; } Here the syntax x: number, y: number means that the function can accept two argum...

Example: function hello(name: string): string { return `Hello ${name}!`; } Here the syntax name: string means that the function can accept one name argument and this argument can only be string and (...): string { means that the return value can only be a string Usage: hello('StackOverfl...

TeX formulae can be inserted in the plot using the rc function import matplotlib.pyplot as plt plt.rc(usetex = True) or accessing the rcParams: import matplotlib.pyplot as plt params = {'tex.usetex': True} plt.rcParams.update(params) TeX uses the backslash \ for commands and symbols, whic...

You can search Docker Hub for images by using the search command: docker search <term> For example: $ docker search nginx NAME DESCRIPTION STARS OFFICIAL AUTOMATED nginx Official build of Nginx. ...

public class MyObject{ public DateTime? TestDate { get; set; } public Func<MyObject, bool> DateIsValid = myObject => myObject.TestDate.HasValue && myObject.TestDate > DateTime.Now; public void DoSomething(){ //We can do this: if(this.TestDate....

Dart has a robust async library, with Future, Stream, and more. However, sometimes you might run into an asynchronous API that uses callbacks instead of Futures. To bridge the gap between callbacks and Futures, Dart offers the Completer class. You can use a Completer to convert a callback into a Fut...

When defining a function, use {param1, param2, …} to specify named parameters: void enableFlags({bool bold, bool hidden}) { // ... } When calling a function, you can specify named parameters using paramName: value enableFlags(bold: true, hidden: false);

If you want to access a workbook that's already open, then getting the assignment from the Workbooks collection is straightforward: dim myWB as Workbook Set myWB = Workbooks("UsuallyFullPathnameOfWorkbook.xlsx") If you want to create a new workbook, then use the Workbooks collection o...