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You can concatenate std::strings using the overloaded + and += operators. Using the + operator: std::string hello = "Hello"; std::string world = "world"; std::string helloworld = hello + world; // "Helloworld" Using the += operator: std::string hello = "Hel...

Use the filesystem module for all file operations: const fs = require('fs'); With Encoding In this example, read hello.txt from the directory /tmp. This operation will be completed in the background and the callback occurs on completion or failure: fs.readFile('/tmp/hello.txt', { encoding: '...

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...

Use Case CASE can be used in conjunction with SUM to return a count of only those items matching a pre-defined condition. (This is similar to COUNTIF in Excel.) The trick is to return binary results indicating matches, so the "1"s returned for matching entries can be summed for a count o...

in myapp/context_processors.py: from django.conf import settings def debug(request): return {'DEBUG': settings.DEBUG} in settings.py: TEMPLATES = [ { ... 'OPTIONS': { 'context_processors': [ ... 'myapp.context_processor...

Common values from both sets: You can use the intersect(_:) method to create a new set containing all the values common to both sets. let favoriteColors: Set = ["Red", "Blue", "Green"] let newColors: Set = ["Purple", "Orange", "Green"] ...

Counter is a dict sub class that allows you to easily count objects. It has utility methods for working with the frequencies of the objects that you are counting. import collections counts = collections.Counter([1,2,3]) the above code creates an object, counts, which has the frequencies of all ...

collections.defaultdict(default_factory) returns a subclass of dict that has a default value for missing keys. The argument should be a function that returns the default value when called with no arguments. If there is nothing passed, it defaults to None. >>> state_capitals = collections.d...

When a user subscribes to a channel, you may want to set state for that newly subscribed user. While there is a subscribe with state API, there are some scenarios where this is not the most optimal/reliable technique (like during a disconnect/reconnect situation - the state will be lost and not rein...

An element can be cloned by invoking the cloneNode method on it. If the first parameter passed to cloneNode is true, the children of the original will also be cloned. var original = document.getElementsByTagName("li")[0]; var clone = original.cloneNode(true);

Function overloading is having multiple functions declared in the same scope with the exact same name exist in the same place (known as scope) differing only in their signature, meaning the arguments they accept. Suppose you are writing a series of functions for generalized printing capabilities, b...

UIButtons can be initialized in a frame: Swift let button = UIButton(frame: CGRect(x: x, y: y, width: width, height: height) Objective C UIButton *button = [[UIButton alloc] initWithFrame:CGRectMake(x, y, width, height)]; A specific type of UIButton can be created like this: Swift let but...

Swift //Align contents to the left of the frame button.contentHorizontalAlignment = .left //Align contents to the right of the frame button.contentHorizontalAlignment = .right //Align contents to the center of the frame button.contentHorizontalAlignment = .center //Make contents fill th...

The easiest way to get up and running is to install Git for Windows from this download page, and select "Use Git and optional Unix tools from the Windows Command Prompt" as in the screenshot below. After this, meteor admin get-machine <os-architecture> will work exactly as it does...

The datepicker is used to show an interactive date selector which is tied to a standard form input field. It makes selecting of date for input tasks very easy and also it is also highly configurable. Any input field can be bound with jquery-ui datepicker by the input field's selector (id,class etc....

To get the physical size of the screen (including window chrome and menubar/launcher): var width = window.screen.width, height = window.screen.height;

To determine the color and pixel depths of the screen: var pixelDepth = window.screen.pixelDepth, colorDepth = window.screen.colorDepth;

A common pitfall is confusing the equality comparison operators is and ==. a == b compares the value of a and b. a is b will compare the identities of a and b. To illustrate: a = 'Python is fun!' b = 'Python is fun!' a == b # returns True a is b # returns False a = [1, 2, 3, 4, 5] b = a ...

Standard Collections Java Collections framework A simple way to construct a List from individual data values is to use java.utils.Arrays method Arrays.asList: List<String> data = Arrays.asList("ab", "bc", "cd", "ab", "bc", "cd"); ...

If you are using the PASSWORD_DEFAULT method to let the system choose the best algorithm to hash your passwords with, as the default increases in strength you may wish to rehash old passwords as users log in <?php // first determine if a supplied password is valid if (password_verify($plaintex...