Tutorial by Examples: er

Note that these only work in the developer tools of certain browsers. $_ gives you the value of whatever expression was evaluated last. "foo" // "foo" $_ // "foo" $0 refers to the DOM element currently selected in the Inspector. So if &l...

In this type of image addition, one image can be used several times without duplicating its URL, making it a good choice when using one image multiple times in a document. Markdown Source Picture of Duck: ![Duck][1] Same picture of Duck: ![Same Duck][1] [1]: http://i.stack.imgur.com/uk...

While object property notation is usually written as myObject.property, this will only allow characters that are normally found in JavaScript variable names, which is mainly letters, numbers and underscore (_). If you need special characters, such as space, ☺, or user-provided content, this is poss...

Sometimes the property name needs to be stored into a variable. In this example, we ask the user what word needs to be looked up, and then provide the result from an object I've named dictionary. var dictionary = { lettuce: 'a veggie', banana: 'a fruit', tomato: 'it depends on who yo...

To find a character or another string, you can use std::string::find. It returns the position of the first character of the first match. If no matches were found, the function returns std::string::npos std::string str = "Curiosity killed the cat"; auto it = str.find("cat"); ...

An array can easily be converted into a std::vector by using std::begin and std::end: C++11 int values[5] = { 1, 2, 3, 4, 5 }; // source array std::vector<int> v(std::begin(values), std::end(values)); // copy array to new vector for(auto &x: v) std::cout << x << &q...

When you start a thread, it will execute until it is finished. Often, at some point, you need to (possibly - the thread may already be done) wait for the thread to finish, because you want to use the result for example. int n; std::thread thread{ calculateSomething, std::ref(n) }; //Doing some...

You cannot pass a reference (or const reference) directly to a thread because std::thread will copy/move them. Instead, use std::reference_wrapper: void foo(int& b) { b = 10; } int a = 1; std::thread thread{ foo, std::ref(a) }; //'a' is now really passed as reference thread.join()...

std::this_thread is a namespace which has functions to do interesting things on the current thread from function it is called from. FunctionDescriptionget_idReturns the id of the threadsleep_forSleeps for a specified amount of timesleep_untilSleeps until a specific timeyieldReschedule running threa...

What are Array-like Objects? JavaScript has "Array-like Objects", which are Object representations of Arrays with a length property. For example: var realArray = ['a', 'b', 'c']; var arrayLike = { 0: 'a', 1: 'b', 2: 'c', length: 3 }; Common examples of Array-like Objects...

To get info from the requesting url (notice that req is the request object in the handler function of routes). Consider this route definition /settings/:user_id and this particular example /settings/32135?field=name // get the full path req.originalUrl // => /settings/32135?field=name // get...

The STUFF() function inserts a string into another string by first deleting a specified number of characters. The following example, deletes "Svr" and replaces it with "Server". This happens by specifying the start_position and length of the replacement. SELECT STUFF('SQL Svr D...

Apple's Reachability class periodically checks the network status and alerts observers to changes. Reachability *internetReachability = [Reachability reachabilityForInternetConnection]; [internetReachability startNotifier];

Reachability uses NSNotification messages to alert observers when the network state has changed. Your class will need to become an observer. [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(reachabilityChanged:) name:kReachabilityChangedNotification object:nil]; Elsewher...

- (void)reachabilityChanged:(NSNotification *)note { Reachability* reachability = [note object]; NetworkStatus netStatus = [reachability currentReachabilityStatus]; if (netStatus == NotReachable) { NSLog(@"Network unavailable"); } }

- (void)reachabilityChanged:(NSNotification *)note { Reachability* reachability = [note object]; NetworkStatus netStatus = [reachability currentReachabilityStatus]; switch (netStatus) { case NotReachable: NSLog(@"Network unavailable"); br...

This example demonstrates how Angular expressions are evaluated when using type="text" and type="number" for the input element. Consider the following controller and view: Controller var app = angular.module('app', []); app.controller('ctrl', function($scope) { $sco...

// Java: String joined = things.stream() .map(Object::toString) .collect(Collectors.joining(", ")); // Kotlin: val joined = things.joinToString() // ", " is used as separator, by default

// Java: List<String> namesOfMaleMembersCollect = roster .stream() .filter(p -> p.getGender() == Person.Sex.MALE) .map(p -> p.getName()) .collect(Collectors.toList()); // Kotlin: val namesOfMaleMembers = roster.filter { it.gender == Person.Sex.MALE }.map { it.nam...

// Java: Map<Person.Sex, List<String>> namesByGender = roster.stream().collect( Collectors.groupingBy( Person::getGender, Collectors.mapping( Person::getName, Collectors.toList()))); // ...