Tutorial by Examples: am

# will retrieve my home path ENV['HOME'] # => "/Users/username" # will try retrieve the 'FOO' environment variable. If failed, will get 'bar' ENV.fetch('FOO', 'bar')

In Normal, type the following to delete a range of lines into a named register :10,20d a This will delete lines 10,20 in register "a. We can verify this by typing :reg This will show the text that was delete in register "a. To paste the contents in "a, just type "ap ...

private final OkHttpClient client = new OkHttpClient(); public void run() throws Exception { RequestBody formBody = new FormBody.Builder() .add("search", "Jurassic Park") .build(); Request request = new Request.Builder() .url("https:...

private static final String IMGUR_CLIENT_ID = "..."; private static final MediaType MEDIA_TYPE_PNG = MediaType.parse("image/png"); private final OkHttpClient client = new OkHttpClient(); public void run() throws Exception { // Use the imgur image upload API as ...

As with docopt, with [docopt_dispatch] you craft your --help in the __doc__ variable of your entry-point module. There, you call dispatch with the doc string as argument, so it can run the parser over it. That being done, instead of handling manually the arguments (which usually ends up in a high c...

The following example shows how to use a QTimer to call a slot every 1 second. In the example, we use a QProgressBar to update its value and check the timer is working properly. main.cpp #include <QApplication> #include "timer.h" int main(int argc, char *argv[]) { QApp...

DATEPART returns the specified datepart of the specified datetime expression as a numeric value. DATENAME returns a character string that represents the specified datepart of the specified date. In practice DATENAME is mostly useful for getting the name of the month or the day of the week. There a...

Using the DATEADD and DATEDIFF functions, it's possible to return the last date of a month. SELECT DATEADD(d, -1, DATEADD(m, DATEDIFF(m, 0, '2016-09-23') + 1, 0)) -- 2016-09-30 00:00:00.000 SQL Server 2012 The EOMONTH function provides a more concise way to return the last date of a month, and...

Sometimes when destructuring maps, you would like to bind the destructured values to their respective key name. Depending on the granularity of the data structure, using the standard destructuring scheme may be a little bit verbose. Let's say, we have a map based record like so : (def john {:lastn...

Vlookup finds some value in the leftmost column of a range and returns a value some number of columns to the right and in the same row. Let's say you want to find the surname of Employee ID 2 from this table: =VLOOKUP(2,$A$2:$C$4,3,0) The value you're retrieving data for is 2 The table you...

This example shows how a MongoDB collection can be displayed in a React component. The collection is continuously synchronized between server and client, and the page instantly updates as database contents change. To connect React components and Meteor collections, you'll need the react-meteor-data...

A very useful feature many people overlook is the ability to construct a Map using a SOQL query. Map<Id, Account> accounts = new Map<Id, Account>([SELECT Id, Name FROM Account]); System.debug(accounts); When you run this code, accounts then contains a Map of your Account objects, ke...

Instead of struct IShape { virtual ~IShape() = default; virtual void print() const = 0; virtual double area() const = 0; virtual double perimeter() const = 0; // .. and so on }; Visitors can be used: // The concrete shapes struct Square; struct Circle; // The v...

First thing to do is enable the mod rewrite on wamp go to Apache modules and scroll down the list If not showing tick enable it and then restart all servers. Linux users can also use below terminal command to enable rewrite module sudo a2enmod rewrite Then restart apache using: sudo service...

The GHC compiler has mature support for compiling with profiling annotations. Using the -prof and -fprof-auto flags when compiling will add support to your binary for profiling flags for use at runtime. Suppose we have this program: main = print (fib 30) fib n = if n < 2 then 1 else fib (n-1)...

When you also want to expose metadata without a config file you can build on the example programmatically creating a ServiceHost: public ConsoleHost() { mHost = new ServiceHost(typeof(Example), new Uri("http://localhost:8000/Example"), new Uri("net.tcp://9000/Example")); ...

A local name for an import can be given, through which all references to the module's symbols must be qualified with: import io = std.stdio; void main() { io.writeln("Hello world"); std.stdio.writeln("hello!"); // error, std is undefined writeln("hello!&qu...

Selective imports may also be renamed. void main() { import std.stdio : fooln = writeln; fooln("Hello world"); }

You can re-use a moved object: void consumingFunction(std::vector<int> vec) { // Some operations } int main() { // initialize vec with 1, 2, 3, 4 std::vector<int> vec{1, 2, 3, 4}; // Send the vector by move consumingFunction(std::move(vec)); // Here...

Dictionaries map keys to values. car = {} car["wheels"] = 4 car["color"] = "Red" car["model"] = "Corvette" Dictionary values can be accessed by their keys. print "Little " + car["color"] + " " + car["model&q...