Tutorial by Examples: an

First it is important to understand that the Core Data Model is the *.xcdatamodeld file. You will notice you have not entities. You will have to create one yourself. At the bottom of Xcode you will notice a button that says "Add Entity" click it and you will have a new entity in the ...

Hibernate has some strategies of inheritance. The JOINED inheritance type do a JOIN between the child entity and parent entity. The problem with this approach is that Hibernate always bring the data of all involved tables in the inheritance. Per example, if you have the entities Bicycle and Mounta...

The map operation is a useful tool when working with arrays and vectors, but it can also be used to deal with Option values in a functional way. fn main() { // We start with an Option value (Option<i32> in this case). let some_number = Some(9); // Let's do some consecutive ...

To create a CSS triangle define an element with a width and height of 0 pixels. The triangle shape will be formed using border properties. For an element with 0 height and width the 4 borders (top, right, bottom, left) each form a triangle. Here's an element with 0 height/width and 4 different color...

Circle To create a circle, define an element with an equal width and height (a square) and then set the border-radius property of this element to 50%. HTML <div class="circle"></div> CSS .circle { width: 50px; height: 50px; background: rgb(246, 156, 85); ...

A closure can be defined with a typealias. This provides a convenient type placeholder if the same closure signature is used in multiple places. For example, common network request callbacks or user interface event handlers make great candidates for being "named" with a type alias. public...

In most cases you want to define several border properties (border-width, border-style and border-color) for all sides of an element. Instead of writing: border-width: 1px; border-style: solid; border-color: #000; You can simply write: border: 1px solid #000; These shorthands are also ava...

iota can be used in expressions, so it can also be used to assign values other than simple incrementing integers starting from zero. To create constants for SI units, use this example from Effective Go: type ByteSize float64 const ( _ = iota // ignore first value by assigning to b...

Because iota is incremented after each ConstSpec, values within the same expression list will have the same value for iota: const ( bit0, mask0 = 1 << iota, 1<<iota - 1 // bit0 == 1, mask0 == 0 bit1, mask1 // bit1 == 2, mask1 == 1 _, _ ...

Changing some CSS attribute will trigger the browser to synchronously calculate the style and layout, which is a bad thing when you need to animate at 60fps. DON'T Animate with left and top trigger layout. #box { left: 0; top: 0; transition: left 0.5s, top 0.5s; position: absolute; ...

To setup a new credential profile with the name myprofile: $ aws configure --profile myprofile AWS Access Key ID [None]: ACCESSKEY AWS Secret Access Key [None]: SECRETKEY Default region name [None]: REGIONNAME Default output format [None]: text | table | json For the AWS access key id and se...

In ASP.NET Core there are several different ways we can localize/globalize our app. It's important to pick a way that suits your needs. In this example you'll see how we can make a multilingual ASP.NET Core app that reads language specific strings from .json files and store them in memory to provi...

Type erasure is a way to hide the type of an object from code using it, even though it is not derived from a common base class. In doing so, it provides a bridge between the worlds of static polymorphism (templates; at the place of use, the exact type must be known at compile time, but it need not b...

import random probability = 0.3 if random.random() < probability: print("Decision with probability 0.3") else: print("Decision with probability 0.7")

Instantiating a socket can be done in various ways. by 2 line declaration & instantiation: First we need to define a variable which will hold a Socket class object: Socket socket; then we can create a Socket class object: socket = new Socket(); We can also make a one line defin...

A subprogram (which defines a procedure), can be either a subroutine or a function; it is said to be an internal subprogram if it is called or invoked from the same program or subprogram that contains it, as follows program my_program ! declarations ! executable statements, ! among which...

A subprogram is said to be external when it is not contained in the main program, nor in a module or antoher subprogram. In particular it can be defined by means of a programming language other than Fortran. When an external subprogram is invoked, the compiler cannot access to its code, so all the ...

string str = "this--is--a--complete--sentence"; string[] tokens = str.Split(new[] { "--" }, StringSplitOptions.None); Result: [ "this", "is", "a", "complete", "sentence" ]

Logistic regression is a particular case of the generalized linear model, used to model dichotomous outcomes (probit and complementary log-log models are closely related). The name comes from the link function used, the logit or log-odds function. The inverse function of the logit is called the lo...

When an exception is thrown from within a Future, you can (should) use recover to handle it. For instance, def runFuture: Future = Future { throw new FairlyStupidException } val itWillBeAwesome: Future = runFuture ...will throw an Exception from within the Future. But seeing as we can predic...