Tutorial by Examples: at

Calculate Single Value from Array in Javascript

var arr = [1, 2, 3, 4, 5]; var sum = arr.reduce((prev, curr) => prev + curr); console.log(sum); // Output: 15 You can also specify an initial value var arr = [1, 2, 3, 4, 5]; var sum = arr.reduce(function (previousValue, currentValue, currentIndex, array) { return previousValue + cur...

arrays • Various ways of accessing arrays

Prevent sensitive methods from being called in templates

When an object is exposed to the template context, its arguments-less methods are available. This is useful when these functions are "getters". But it can be hazardeous if these methods alter some data or have some side effects. Eventhough you likely trust the template writer, he may not b...

Django • Templating

Create File

File static class By using Create method of the File static class we can create files. Method creates the file at the given path, at the same time it opens the file and gives us the FileStream of the file. Make sure you close the file after you are done with it. ex1: var fileStream1 = File.Create...

C# Language • File and Stream I/O

Print out float using the Image attribute

Ada 2012(TC-1) with Ada.Text_IO; procedure Main is type Some_Float digits 8 range 0.0 .. 10.0; X : Some_Float := 2.71; begin Ada.Text_IO.Put_Line (X'Image); end Main; Result 2.71000E+00

ada • Attribute Image

Print out integer using the Image attribute

Ada 2012(TC-1) with Ada.Text_IO; procedure Main is type Some_Integer is range -42 .. 42; X : Some_Integer := 17; begin Ada.Text_IO.Put_Line (X'Image); end Main; Result 17

ada • Attribute Image

Print out enumeration using the Image attribute

Ada 2012(TC-1) with Ada.Text_IO; procedure Main is type Fruit is (Banana, Orange, Pear); X : Fruit := Orange; begin Ada.Text_IO.Put_Line (X'Image); Ada.Text_IO.Put_Line (Pear'Image); end Main; Result ORANGE PEAR

ada • Attribute Image

Use what the language offers: the if/else construct.

Well, if you want a switch/case construct, the most straightforward way to go is to use the good old if/else construct: def switch(value): if value == 1: return "one" if value == 2: return "two" if value == 42: return "the answer to...

Python Language • Alternatives to switch statement from other languages

Bulkification

If you do row-by-row processing in Salesforce, you'll probably reach the governor limit quickly. This is especially true with triggers and things that fire when you don't expect them. One documented method of escaping the governor limit is bulkification. Note: The following information is based on ...

Salesforce • Trigger Bulkification

Installation or Setup

Chart.js can be included in several different ways: NPM Run the following command on your NPM project directory npm install chart.js --save CDN Include a script tag in your HTML linking to the chart.js CDN <html> <body> <script type="text/javascript" s...

chart.js • Getting started with chart.js

How to know the directory and/or the path of the file you are editing

To know the path of the directory your file is in you can use: Esc to enter command mode :pwd This will print the path to the directory at the bottom of the editor, like this I'm a ninja ~ ~ ~ ~ ~ /home/ubuntu/myfolder 1,5 All Now...

vim • Tips and tricks to boost productivity

Sample to get user profile path

# will retrieve my home path ENV['HOME'] # => "/Users/username" # will try retrieve the 'FOO' environment variable. If failed, will get 'bar' ENV.fetch('FOO', 'bar')

Ruby Language • Environment Variables

Formatting console output

Many of the console's print methods can also handle C-like string formatting, using % tokens: console.log('%s has %d points', 'Sam', 100); Displays Sam has 100 points. The full list of format specifiers in Javascript is: SpecifierOutput%sFormats the value as a string%i or %dFormats the value a...

JavaScript • Console

Limit DOM Updates

A common mistake seen in JavaScript when run in a browser environment is updating the DOM more often than necessary. The issue here is that every update in the DOM interface causes the browser to re-render the screen. If an update changes the layout of an element in the page, the entire page layout...

JavaScript • Performance Tips

Set a custom date format

Default date format: "mm/dd/yy" The following example shows how you can set the date format in initialization with the dateFormat option. <input type="text" id="datepicker"> <script> $("#datepicker").datepicker({ dateFormat: "...

jQuery UI Library • Datepicker

Matching an exact string

let fetchRequest = NSFetchRequest(entityName: "Foo") var thePredicate: NSPredicate? thePredicate = NSPredicate(format: "message == 'example'") The entity Foo has a message string attribute

core-data • Using Predicates

switch () Statements

switch statements are useful when you want to have your program do many different things according to the value of a particular test variable. An example usage of switch statement is like this: int a = 1; switch (a) { case 1: puts("a is 1"); break; case 2: puts("...

C Language • Selection Statements

Target attribute in form tag

The target attribute specifies a name or a keyword that indicates where to display the response that is received after submitting the form. The target attribute defines a name of, or keyword for, a browsing context (e.g. tab, window, or inline frame). From Tag with a target attribute: <form ta...

HTML • Forms

Generic Static Constructors

If the type on which the static constructor is declared is generic, the static constructor will be called once for each unique combination of generic arguments. class Animal<T> { static Animal() { Console.WriteLine(typeof(T).FullName); } public static void Yawn...

C# Language • Constructors and Finalizers

Print out Enumeration using attribute Image

with Ada.Text_IO; procedure Main is type Fruit is (Banana, Orange, Pear); X : Fruit := Orange; begin Ada.Text_IO.Put_Line (Fruit'Image (X)); end Main; Result ORANGE

ada • Attribute Image

Print out Integer using attribute Image

with Ada.Text_IO; procedure Main is X : Integer := 17; begin Ada.Text_IO.Put_Line (Integer'Image (X)); end Main; Result 17

ada • Attribute Image