Tutorial by Examples: n

First off, let's assume this is your initial model, inside an application called discography: from django.db import models class Album(models.Model): name = models.CharField(max_length=255) artist = models.CharField(max_length=255) Now, you realize that you want to use a ForeignKey ...

You could describe variable affectation in different ways. Typed int a = 1 int a := 1 let int a = 1 int a <- 1 No type a = 1 a := 1 let a = 1 a <- 1

As long as the function name, return statement and parameters are clear, you're fine. def incr n return n + 1 or let incr(n) = n + 1 or function incr (n) return n + 1 are all quite clear, so you may use them. Try not to be ambiguous with a variable affectation

An example implementation of BubbleSort in C++: void bubbleSort(vector<int>numbers) { for(int i = numbers.size() - 1; i >= 0; i--) { for(int j = 1; j <= i; j++) { if(numbers[j-1] > numbers[j]) { swap(numbers[j-1],numbers(...

The BigInteger class has a constructor dedicated to generate random BigIntegers, given an instance of java.util.Random and an int that specifies how many bits will the BigInteger have. Its usage is quite simple - when you call the constructor BigInteger(int, Random) like this: BigInteger randomBigI...

By utilizing the pre_save we can determine if a save action on our database was about updating an existing object or creating a new one. In order to achieve this you can check the state of the model object: @receiver(pre_save, sender=User) def pre_save_user(sender, instance, **kwargs): ...

Download the .jar file from vaadin add-ons And put it in the lib folder of WEB-INF then right click on the .jar file and click on to Build Path --> Add To Build Path

public class QuickSort { private static int Partition(int[] input, int low, int high) { var pivot = input[high]; var i = low - 1; for (var j = low; j <= high - 1; j++) { if (input[j] <= pivot) { i++; ...

Objective-C Add the delegate and a text-formatter to the ViewController.h file @interface ViewController : UIViewController <UIPrintInteractionControllerDelegate> { UISimpleTextPrintFormatter *_textFormatter; } In the ViewController.m file define the following constants #define Def...

In C, all arguments are passed to functions by value, including structs. For small structs, this is a good thing as it means there is no overhead from accessing the data through a pointer. However, it also makes it very easy to accidentally pass a huge struct resulting in poor performance, particula...

An example of a constraint as expressed in the C standard is having two variables of the same name declared in a scope1), for example: void foo(int bar) { int var; double var; } This code breaches the constraint and must produce a diagnostic message at compile time. This is very usef...

The unary + and - operators are only usable on arithmetic types, therefore if for example one tries to use them on a struct the program will produce a diagnostic eg: struct foo { bool bar; }; void baz(void) { struct foo testStruct; -testStruct; /* This breaks the constraint so mu...

Different countries have different number formats and considering this we can have different formats using Locale of java. Using locale can help in formatting Locale locale = new Locale("en", "IN"); NumberFormat numberFormat = NumberFormat.getInstance(locale); using above fo...

We have a DataListComponent that shows a data we pull from a service. DataListComponent also has a PagerComponent as it's child. PagerComponent creates page number list based on total number of pages it gets from the DataListComponent. PagerComponent also lets the DataListComponent know when user c...

Detailed instructions on getting microcontroller set up or installed.

(defun sum-list-integers (list) (reduce '+ list)) ; 10 (sum-list-integers '(1 2 3 4)) ; 55 (sum-list-integers '(1 2 3 4 5 6 7 8 9 10))

Consider this example: private void button1_Click(object sender, EventArgs e) { label1.Text = RunTooLong(); } This method will freeze UI application until the RunTooLong will be completed. The application will be unresponsive. You can try run inner code asynchronously: private void butt...

The members of a union share the same space in memory. This means that writing to one member overwrites the data in all other members and that reading from one member results in the same data as reading from all other members. However, because union members can have differing types and sizes, the da...

Install Anaconda(PyQt5 is build-in), especially for windows user. Integrate QtDesigner and QtUIConvert in PyCharm(External Tools) Open PyCharm Settings > Tools > External Tools Create Tool(QtDesigner) - used to edit *.ui files Create Tool(PyUIConv) - used to convert *.ui to *.py ...

Carthage Setup Download the latest version of Carthage from the given link Download Link Down in the Download section download the Carthage.pkg file. Once the download is complete install it by double clinking on the download pkg file. To check for successful download run the following command i...