Tutorial by Examples: r

The pygame.mixer module helps control the music used in pygame programs. As of now, there are 15 different functions for the mixer module. Initializing Similar to how you have to initialize pygame with pygame.init(), you must initialize pygame.mixer as well. By using the first option, we initiali...

While chrome browser is open to any tab (except welcome tabs) you have three options to open Chrome Dev Tools: Keyboard: Type command ⌘+option+i Browser Menu: Click 'Menu' > 'More Tools' > 'Developer Tools' Program Menu (at top of your screen): Click 'View' > 'Developer' > 'Develope...

You use the FIRST_VALUE function to determine the first value in an ordered result set, which you identify using a scalar expression. SELECT StateProvinceID, Name, TaxRate,        FIRST_VALUE(StateProvinceID)         OVER(ORDER BY TaxRate ASC) AS FirstValue FROM SalesTaxRate; In this example,...

The PERCENT_RANK function calculates the ranking of a row relative to the row set. The percentage is based on the number of rows in the group that have a lower value than the current row. The first value in the result set always has a percent rank of zero. The value for the highest-ranked – or last...

The PERCENTILE_DISC function lists the value of the first entry where the cumulative distribution is higher than the percentile that you provide using the numeric_literal parameter. The values are grouped by rowset or partition, as specified by the WITHIN GROUP clause. The PERCENTILE_CONT functi...

Lets following are the class definition class A def a; end end module B def b; end end class C < A include B def c; end end What are the instance methods of C? C.instance_methods # [:c, :b, :a, :to_json, :instance_of?...] What are the instance methods that declare...

var passport = require('passport'); var LocalStrategy = require('passport-local').Strategy; passport.serializeUser(function(user, done) { //In serialize user you decide what to store in the session. Here I'm storing the user id only. done(null, user.id); }); passport.deserializeUser(funct...

This is a complete example of all the commonly used SQLite related APIs. The aim is to get you up and running really fast. You can also get a runnable PHP file of of this tutorial. Creating/opening a database Let's create a new database first. Create it only if the file doesn't exist and open it f...

Haystack: The string in which given pattern needs to be searched. Needle: The pattern to be searched. Time complexity: Search portion (strstr method) has the complexity O(n) where n is the length of haystack but as needle is also pre parsed for building prefix table O(m) is required for building p...

Detailed instructions on getting nuget set up or installed.

When asking Apache Spark related questions please include following information Apache Spark version used by the client and Spark deployment if applicable. For API related questions major (1.6, 2.0, 2.1 etc.) is typically sufficient, for questions concerning possible bugs always use full version ...

Debugging questions. When question is related to debugging specific exception always provide relevant traceback. While it is advisable to remove duplicated outputs (from different executors or attempts) don't cut tracebacks to a single line or exception class only. Performance questions. Dependin...

Search Stack Overflow for duplicate questions. There common class of problems which have been already extensively documented. Read How do I ask a good question?. Read What topics can I ask about here? Apache Spark Community resources

The Go Playground One little known Go tool is The Go Playground. If one wants to experiment with Go without downloading it, they can easily do so simply by . . . Visiting the Playground in their web browser Entering their code Clicking “Run” Sharing your code The Go Playground also has too...

What is floating point? There are two types of numbers: fixed point where a certain number of digits are available before and after the radix point. floating point where a certain number of digits are available for the mantissa and for the exponent. An example using decimal digits with three...

An example of a configuration function in SQL is the @@SERVERNAME function. This function provides the name of the local server that's running SQL. SELECT @@SERVERNAME AS 'Server' ServerSQL064 In SQL, most data conversions occur implicitly, without any user intervention. To perform any convers...

In your routes/index.js Here user is the model for the userSchema router.post('/login', function(req, res, next) { if (!req.body.username || !req.body.password) { return res.status(400).json({ message: 'Please fill out all fields' }); } passpor...

A common requirement for a Java application is that can be deployed by copying a single file. For simple applications that depend only on the standard Java SE class libraries, this requirement is satisfied by creating a JAR file containing all of the (compiled) application classes. Things are not ...

package main import ( "encoding/gob" "os" ) type User struct { Username string Password string } func main() { user := User{ "zola", "supersecretpassword", } file, _ := os.Create("user.go...

package main import ( "encoding/gob" "fmt" "os" ) type User struct { Username string Password string } func main() { user := User{} file, _ := os.Open("user.gob") defer file.Close() decoder := gob...