Tutorial by Examples: re

Functions can take inputs in form of variables that can be used and assigned inside their own scope. The following function takes two numeric values and returns their sum: function addition (argument1, argument2){ return argument1 + argument2; } console.log(addition(2, 3)); // -> 5 ...

x = [5, 5, 1, 3] y = [5, 2, 4, 3] Union (|) contains elements from both arrays, with duplicates removed: x | y => [5, 1, 3, 2, 4] Intersection (&) contains elements which are present both in first and second array: x & y => [5, 3] Difference (-) contains elements which ar...

Note: Before deciding which Stream to use please have a look at ParallelStream vs Sequential Stream behavior. When you want to perform Stream operations concurrently, you could use either of these ways. List<String> data = Arrays.asList("One", "Two", "Three", &q...

While using scaffolding is a fast and easy if you are new to Rails or you are creating a new application, later it can be useful just to do it on your own ato avoid the need to go through the scaffold-generated code to slim it down (remove unused parts, etc.). Creating a model can be as simple as c...

Ruby on Rails provides a model generator you can use to create ActiveRecord models. Simply use rails generate model and provide the model name. $ rails g model user In addition to the model file in app/models, the generator will also create: the Test in test/models/user_test.rb the Fixtures ...

In Python 2, reduce is available either as a built-in function or from the functools package (version 2.6 onwards), whereas in Python 3 reduce is available only from functools. However the syntax for reduce in both Python2 and Python3 is the same and is reduce(function_to_reduce, list_to_reduce). A...

Simple: NSString *newString = @"My String"; From multiple strings: NSString *stringOne = @"Hello"; NSString *stringTwo = @"world"; NSString *newString = [NSString stringWithFormat:@"My message: %@ %@", stringOne, stringTwo]; Usi...

The main difference is that double-quoted String literals support string interpolations and the full set of escape sequences. For instance, they can include arbitrary Ruby expressions via interpolation: # Single-quoted strings don't support interpolation puts 'Now is #{Time.now}' # Now is #{Time...

Ruby provides several ways to create a String object. The most common way is using single or double quotes to create a "string literal": s1 = 'Hello' s2 = "Hello" The main difference is that double-quoted string literals are a little bit more flexible as they support interpo...

Tuples are created using generic types Tuple<T1>-Tuple<T1,T2,T3,T4,T5,T6,T7,T8>. Each of the types represents a tuple containing 1 to 8 elements. Elements can be of different types. // tuple with 4 elements var tuple = new Tuple<string, int, bool, MyClass>("foo", 123, t...

In Python 2, range function returns a list while xrange creates a special xrange object, which is an immutable sequence, which unlike other built-in sequence types, doesn't support slicing and has neither index nor count methods: Python 2.x2.3 print(range(1, 10)) # Out: [1, 2, 3, 4, 5, 6, 7, 8, 9...

Use the following steps to create a topic: Click Create New Topic on the tag's dashboard. Name the topic. Provide detailed examples in the "Examples" section. If you have more to share, use the "Syntax," "Parameters," and "Remarks" sections. You have ...

angular .module('app') .controller('SampleController', SampleController) SampleController.$inject = ['$log', '$scope']; function SampleController($log, $scope){ $log.debug('*****SampleController******'); /* Your code below */ } Note: The .$inject will make sure your...

There are a couple different ways to protect your controller creation from minification. The first is called inline array annotation. It looks like the following: var app = angular.module('app'); app.controller('sampleController', ['$scope', '$http', function(a, b){ //logic here }]); The...

As long as the element is a block, and it has an explicitly set width value, margins can be used to center block elements on a page horizontally. We add a width value that is lower than the width of the window and the auto property of margin then distributes the remaining space to the left and the ...

In a loop (for, foreach, do, while) the break statement aborts the execution of the innermost loop and returns to the code after it. Also it can be used with yield in which it specifies that an iterator has come to an end. for (var i = 0; i < 10; i++) { if (i == 5) { break; ...

NSDictionary *dict = [[NSDictionary alloc] initWithObjectsAndKeys:@"value1", @"key1", @"value2", @"key2", nil]; or NSArray *keys = [NSArray arrayWithObjects:@"key1", @"key2", nil]; NSArray *objects = [NSArray arrayWithObjects:@"va...

You may need to convert a Stream emitting Optional to a Stream of values, emitting only values from existing Optional. (ie: without null value and not dealing with Optional.empty()). Optional<String> op1 = Optional.empty(); Optional<String> op2 = Optional.of("Hello World");...

The function php_sapi_name() and the constant PHP_SAPI both return the type of interface (Server API) that is being used by PHP. They can be used to restrict the execution of a script to the command line, by checking whether the output of the function is equal to cli. if (php_sapi_name() === 'cli')...

A data.table is an enhanced version of the data.frame class from base R. As such, its class() attribute is the vector "data.table" "data.frame" and functions that work on a data.frame will also work with a data.table. There are many ways to create, load or coerce to a data.table....