Tutorial by Examples: u

There are several possibilities and conventions to name an enumeration. The first is to use a tag name just after the enum keyword. enum color { RED, GREEN, BLUE }; This enumeration must then always be used with the keyword and the tag like this: enum color chosenColor = RE...

C++17 C++17 introduces std::string_view, which is simply a non-owning range of const chars, implementable as either a pair of pointers or a pointer and a length. It is a superior parameter type for functions that requires non-modifiable string data. Before C++17, there were three options for this: ...

NSString *pathToPlist = [[NSBundle mainBundle] pathForResource:@"plistName" ofType:@"plist"]; NSDictionary *plistDict = [[NSDictionary alloc] initWithContentsOfFile:pathToPlist];

It is usually not a good idea to mix signed and unsigned integers in arithmetic operations. For example, what will be output of following example? #include <stdio.h> int main(void) { unsigned int a = 1000; signed int b = -1; if (a > b) puts("a is more than b&quot...

public bool IsTypeNullable<T>() { return Nullable.GetUnderlyingType( typeof(T) )!=null; }

A common usage scenario that this feature really helps with is when you are looking for an object in a collection and need to create a new one if it does not already exist. IEnumerable<MyClass> myList = GetMyList(); var item = myList.SingleOrDefault(x => x.Id == 2) ?? new MyClass { Id = 2...

// define url let url = NSURL(string: "https://urlToGet.com") //create a task to get data from a url let task = NSURLSession.sharedSession().dataTaskWithURL(url!) { /*inside this block, we have access to NSData *data, NSURLResponse *response, and NSError...

This example shows how to use the default logging api. import java.util.logging.Level; import java.util.logging.Logger; public class MyClass { // retrieve the logger for the current class private static final Logger LOG = Logger.getLogger(MyClass.class.getName()); pub...

There are multiple ways to set a key's object in an NSDictionary, corresponding to the ways you get a value. For instance, to add a lamborghini to a list of cars Standard [cars setObject:lamborghini forKey:@"Lamborghini"]; Just like any other object, call the method of NSDictionary th...

There are multiple ways to get an object from an NSDictionary with a key. For instance, to get a lamborghini from a list of cars Standard Car * lamborghini = [cars objectForKey:@"Lamborghini"]; Just like any other object, call the method of NSDictionary that gives you an object for a ...

Represents a thread-safe collection of key/value pairs that can be accessed by multiple threads concurrently. Creating an instance Creating an instance works pretty much the same way as with Dictionary<TKey, TValue>, e.g.: var dict = new ConcurrentDictionary<int, string>(); Ad...

One of the more popular .NET providers for Postgresql is Npgsql, which is ADO.NET compatible and is used nearly identically as other .NET database providers. A typical query is performed by creating a command, binding parameters, and then executing the command. In C#: var connString = "Host=m...

You can use a For Each...Next loop to iterate through any IEnumerable type. This includes arrays, lists, and anything else that may be of type IEnumerable or returns an IEnumerable. An example of looping through a DataTable's Rows property would look like this: For Each row As DataRow In DataTable...

The following example shows how you can use Json.Net to serialize the data in an C# Object's instance, to JSON string. using System; using System.Collections.Generic; using Newtonsoft.Json; public class Employee { public string FirstName { get; set; } public string LastName { get; s...

The following example shows how you can deserialize a JSON string containing into an Object (i.e. into an instance of a class). using System; using System.Collections.Generic; using Newtonsoft.Json; public class Program { public class Employee { public s...

Customizing a UITableViewCell can allow for very powerful, dynamic, and responsive interfaces. With extensive customization and in combination with other techniques you can do things like: update specific properties or interface elements as they change, animate or draw things in the cell, efficientl...

Syntactically, a tuple is a comma-separated list of values: t = 'a', 'b', 'c', 'd', 'e' Although not necessary, it is common to enclose tuples in parentheses: t = ('a', 'b', 'c', 'd', 'e') Create an empty tuple with parentheses: t0 = () type(t0) # <type 'tuple'> To crea...

svc public class WCFRestfulService : IWCFRestfulService { public string GetServiceName(int Id) { return "This is a WCF Restful Service"; } } Interface [ServiceContract(Name = "WCRestfulService ")] public interface IWCFRestf...

Detailed instructions on getting database set up or installed.

If you want to import a module that doesn't already exist as a built-in module in the Python Standard Library nor as a side-package, you can do this by adding the path to the directory where your module is found to sys.path. This may be useful where multiple python environments exist on a host. im...