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First of all, we need to add our first Fragment at the beginning, we should do it in the onCreate() method of our Activity: if (null == savedInstanceState) { getSupportFragmentManager().beginTransaction() .addToBackStack("fragmentA") .replace(R.id.container, FragmentA.n...

Detailed instructions on getting razor set up or installed.

You can use flatMap(_:) in a similar manner to map(_:) in order to create an array by applying a transform to a sequence's elements. extension SequenceType { public func flatMap<T>(@noescape transform: (Self.Generator.Element) throws -> T?) rethrows -> [T] } The difference with...

sed -i s/"what to replace"/"with what to replace"/g $file We use -i to select in-place editing on the $file file. In some systems it is required to add suffix after -i flag which will be used to create backup of original file. You can add empty string like -i '' to omit the b...

ansible -i hosts -m ping targethost -i hosts defines the path to inventory file targethost is the name of the host in the hosts file

Here's how you can destructure a map: (def my-map {:a 1 :b 2 :c 3}) Then, for example, within a let block you can extract values from the map very succinctly as follows: (let [{x :a y :c} my-map] (println ":a val:" x ", :c val: " y)) ;; :a val: 1 , :c val: 3 Notice th...

Create a class inheriting from Exception: class FooException(Exception): pass try: raise FooException("insert description here") except FooException: print("A FooException was raised.") or another exception type: class NegativeError(ValueError): pass ...

Flask has a utility called jsonify() that makes it more convenient to return JSON responses from flask import Flask, jsonify app = Flask(__name__) @app.route('/api/get-json') def hello(): return jsonify(hello='world') # Returns HTTP Response with {"hello": "world"} ...

If the mimetype of the HTTP request is application/json, calling request.get_json() will return the parsed JSON data (otherwise it returns None) from flask import Flask, jsonify app = Flask(__name__) @app.route('/api/echo-json', methods=['GET', 'POST', 'DELETE', 'PUT']) ...

# For Python 2 compatibility. from __future__ import print_function import lxml.html import requests def main(): r = requests.get("https://httpbin.org") html_source = r.text root_element = lxml.html.fromstring(html_source) # Note root_element.xpath() gives a *...

If the values in a container have certain operators already overloaded, std::sort can be used with specialized functors to sort in either ascending or descending order: C++11 #include <vector> #include <algorithm> #include <functional> std::vector<int> v = {5,1,2,4,3};...

class UsersController < ApplicationController def index hashmap_or_array = [{ name: "foo", email: "[email protected]" }] respond_to do |format| format.html { render html: "Hello World" } format.json { render json: hashmap_or_array } en...

Controllers have access to HTTP parameters (you might know them as ?name=foo in URLs, but Ruby on Rails handle different formats too!) and output different responses based on them. There isn't a way to distinguish between GET and POST parameters, but you shouldn't do that in any case. class UsersCo...

class UsersController < ApplicationController def index respond_to do |format| format.html do render html: "Hello #{ user_params[:name] } user_params[:sentence]" end end end private def user_params if params[:name] == "john&quo...

This function runs an AJAX call using GET allowing us to send parameters (object) to a file (string) and launch a callback (function) when the request has been ended. function ajax(file, params, callback) { var url = file + '?'; // loop through object and assemble the url var notFirst ...

To separate a URL into its individual components, use parse_url(): $url = 'http://www.example.com/page?foo=1&bar=baz#anchor'; $parts = parse_url($url); After executing the above, the contents of $parts would be: Array ( [scheme] => http [host] => www.example.com [path...

The StringBuffer, StringBuilder, Formatter and StringJoiner classes are Java SE utility classes that are primarily used for assembling strings from other information: The StringBuffer class has been present since Java 1.0, and provides a variety of methods for building and modifying a "buf...

The following query returns the database options and metadata: select * from sys.databases WHERE name = 'MyDatabaseName';

Generics types can have more than one type parameters, eg. Result is defined like this: pub enum Result<T, E> { Ok(T), Err(E), }

// Only accept T and U generic types that also implement Debug fn print_objects<T: Debug, U: Debug>(a: T, b: U) { println!("A: {:?} B: {:?}", a, b); } print_objects(13, 44); // or annotated explicitly print_objects::<usize, u16>(13, 44); The bounds must cover a...