Tutorial by Examples: st

Basic implementation: <script src= "http://player.twitch.tv/js/embed/v1.js"></script> <div id="PLAYER_DIV_ID"></div> <script type="text/javascript"> var options = { width: 854, height: 480, channel: "...

An if statement checks whether a Bool condition is true: let num = 10 if num == 10 { // Code inside this block only executes if the condition was true. print("num is 10") } let condition = num == 10 // condition's type is Bool if condition { print("num is 10&...

To allow the use of in for custom classes the class must either provide the magic method __contains__ or, failing that, an __iter__-method. Suppose you have a class containing a list of lists: class ListList: def __init__(self, value): self.value = value # Create a set of al...

Counting the keys of a Mapping isn't possible with collections.Counter but we can count the values: from collections import Counter adict = {'a': 5, 'b': 3, 'c': 5, 'd': 2, 'e':2, 'q': 5} Counter(adict.values()) # Out: Counter({2: 2, 3: 1, 5: 3}) The most common elements are avaiable by the m...

alist = [1, 2, 3, 4, 1, 2, 1, 3, 4] alist.count(1) # Out: 3 atuple = ('bear', 'weasel', 'bear', 'frog') atuple.count('bear') # Out: 2 atuple.count('fox') # Out: 0

astring = 'thisisashorttext' astring.count('t') # Out: 4 This works even for substrings longer than one character: astring.count('th') # Out: 1 astring.count('is') # Out: 2 astring.count('text') # Out: 1 which would not be possible with collections.Counter which only counts single char...

class MultiIndexingList: def __init__(self, value): self.value = value def __repr__(self): return repr(self.value) def __getitem__(self, item): if isinstance(item, (int, slice)): return self.__class__(self.value[item]) r...

What is hoisting? Hoisting is a mechanism which moves all variable and function declarations to the top of their scope. However, variable assignments still happen where they originally were. For example, consider the following code: console.log(foo); // → undefined var foo = 42; console.log(fo...

Java SE 7 As the try-catch-final statement example illustrates, resource cleanup using a finally clause requires a significant amount of "boiler-plate" code to implement the edge-cases correctly. Java 7 provides a much simpler way to deal with this problem in the form of the try-with-res...

Employ the EAFP coding style and try to open it. import errno try: with open(path) as f: # File exists except IOError as e: # Raise the exception if it is not ENOENT (No such file or directory) if e.errno != errno.ENOENT: raise # No such file or directory ...

Final classes When used in a class declaration, the final modifier prevents other classes from being declared that extend the class. A final class is a "leaf" class in the inheritance class hierarchy. // This declares a final class final class MyFinalClass { /* some code */ } ...

Convert to String var date1 = new Date(); date1.toString(); Returns: "Fri Apr 15 2016 07:48:48 GMT-0400 (Eastern Daylight Time)" Convert to Time String var date1 = new Date(); date1.toTimeString(); Returns: "07:48:48 GMT-0400 (Eastern Daylight Time)" Conve...

Introduction Package is a term used by npm to denote tools that developers can use for their projects. This includes everything from libraries and frameworks such as jQuery and AngularJS to task runners such as Gulp.js. The packages will come in a folder typically called node_modules, which will a...

You will first need to create a directory, access it in your shell and install Express using npm by running npm install express --save Create a file and name it app.js and add the following code which creates a new Express server and adds one endpoint to it (/ping) with the app.get method: const e...

Python 3.2+ has support for %z format when parsing a string into a datetime object. UTC offset in the form +HHMM or -HHMM (empty string if the object is naive). Python 3.x3.2 import datetime dt = datetime.datetime.strptime("2016-04-15T08:27:18-0500", "%Y-%m-%dT%H:%M:%S%z"...

C++11 The type std::tuple can bundle any number of values, potentially including values of different types, into a single return object: std::tuple<int, int, int, int> foo(int a, int b) { // or auto (C++14) return std::make_tuple(a + b, a - b, a * b, a / b); } In C++17, a braced init...

C++11 The container std::array can bundle together a fixed number of return values. This number has to be known at compile-time and all return values have to be of the same type: std::array<int, 4> bar(int a, int b) { return { a + b, a - b, a * b, a / b }; } This replaces c style ar...

Replace by position To replace a portion of a std::string you can use the method replace from std::string. replace has a lot of useful overloads: //Define string std::string str = "Hello foo, bar and world!"; std::string alternate = "Hello foobar"; //1) str.replace(6, 3,...

const fs = require('fs'); // Read the contents of the directory /usr/local/bin asynchronously. // The callback will be invoked once the operation has either completed // or failed. fs.readdir('/usr/local/bin', (err, files) => { // On error, show it and return if(err) return console.er...

Let's say you've got a list of restaurants -- maybe you read it from a file. You care about the unique restaurants in the list. The best way to get the unique elements from a list is to turn it into a set: restaurants = ["McDonald's", "Burger King", "McDonald's", &qu...