Tutorial by Examples: io

The client first sends a request with an Accept-Encoding header that indicates it supports gzip: GET / HTTP/1.1\r\n Host: www.google.com\r\n Accept-Encoding: gzip, deflate\r\n \r\n The server may then send a response with a compressed response body and a Content-Encoding header that specifies...

R has a set of built in higher order functions: Map, Reduce, Filter, Find, Position, Negate. Map applies a given function to a list of values: words <- list("this", "is", "an", "example") Map(toupper, words) Reduce successively applies a binary functi...

Suppose you want to prevent unauthorized users to access the page then you have to put barrier to them by authorizing access. We can do this by using spring-security which provides basic authentication by securing all HTTP end points. For that you need to add spring-security dependency to your proje...

C99 Since C99, C has variable length arrays, VLA, that model arrays with bounds that are only known at initialization time. While you have to be careful not to allocate too large VLA (they might smash your stack), using pointers to VLA and using them in sizeof expressions is fine. double sumAll(si...

There is a limit to the depth of possible recursion, which depends on the Python implementation. When the limit is reached, a RuntimeError exception is raised: RuntimeError: Maximum Recursion Depth Exceeded Here's a sample of a program that would cause this error: def cursing(depth): try: ...

When the only thing returned from a function is a recursive call, it is refered to as tail recursion. Here's an example countdown written using tail recursion: def countdown(n): if n == 0: print "Blastoff!" else: print n countdown(n-1) Any computat...

By default Python's recursion stack cannot exceed 1000 frames. This can be changed by setting the sys.setrecursionlimit(15000) which is faster however, this method consumes more memory. Instead, we can also solve the Tail Recursion problem using stack introspection. #!/usr/bin/env python2.4 # This...

Dependencies can be added for specific configuration like test/androidTest androidTestCompile 'com.android.support.test.espresso:espresso-core:2.2.1' testCompile 'junit:junit:3.8.1' Alternatively create your own configuration configurations { myconfig } And then download dependency fo...

Sometimes we need to change words position from one place to another or reduce size of the words and change the color of words automatically to improve the attraction of our website or web apps. JQuery helps a lot with this concept using fadeIn(), hide(), slideDown() but its functionality are limite...

To check for location services we need real device but for testing purpose we can also use simulator and add our own location by following below steps: add new GPX file into your project. in GPX file add waypoints like <?xml version="1.0"?> <gpx version="1.1" cre...

private List<FooBar> _fooBars; public List<FooBar> FooBars { get { return _fooBars ?? (_fooBars = new List<FooBar>()); } } The first time the property .FooBars is accessed the _fooBars variable will evaluate as null, thus falling through to the assignment statement ass...

To stop the Handler from execution remove the callback attached to it using the runnable running inside it: Runnable my_runnable = new Runnable() { @Override public void run() { // your code here } }; public Handler handler = new Handler(); // use 'new Handler(Looper.get...

In order to call a function through a function pointer, the function pointer's type must exactly match the function's type. Otherwise, the behaviour is undefined. Example: int f(); void (*p)() = reinterpret_cast<void(*)()>(f); p(); // undefined

OOP - Object Oriented Programming is a vastly used programming paradigm in these days. In OOP, we model real world problems using Objects and there behaviors, in order to solve them, programmatically. There are four main OOP Concepts Inheritance Polymorphism Abstraction Encapsulation These...

To get versionName and versionCode of current build of your application you should query Android's package manager. try { // Reference to Android's package manager PackageManager packageManager = this.getPackageManager(); // Getting package info of this application PackageInfo...

System.assert can be used to check that a boolean expression evaluates to true: System.assert(Service.isActive()); System.assert(!Service.getItems().isEmpty(), 'items should not be empty'); System.assertEquals and System.assertNotEquals can be used to check equality of two values. The expected ...

In Object Oriented Design, objects receive messages and reply to them. In Ruby, sending a message is calling a method and result of that method is the reply. In Ruby message passing is dynamic. When a message arrives rather than knowing exactly how to reply to it Ruby uses a predefined set of rules...

Ruby moves up on ancestors chain of an object. This chain can contain both modules and classes. Same rules about moving up the chain apply to modules as well. class Example end module Prepended def initialize *args return super :default if args.empty? super end end module Fi...

This class is called Greeter. Its responsibility is to output a greeting. It has two dependencies. It needs something that will give it the greeting to output, and then it needs a way to output that greeting. Those dependencies are both described as interfaces, IGreetingProvider and IGreetingWriter....

This builds on the previous example of the Greeter class which has two dependencies, IGreetingProvider and IGreetingWriter. The actual implementation of IGreetingProvider might retrieve a string from an API call or a database. The implementation of IGreetingWriter might display the greeting in the ...