Tutorial by Examples: r

To build a Rails application that will be an API server, you can start with a more limited subset of Rails in Rails 5. To generate a new Rails API app: rails new my_api --api What --api does is to remove functionality that is not needed when building an API. This includes sessions, cookies, ass...

In PHP, there are two versions of logical AND and OR operators. OperatorTrue if$a and $bBoth $a and $b are true$a && $bBoth $a and $b are true$a or $bEither $a or $b is true$a || $bEither $a or $b is true Note that the && and || opererators have higher precedence than and and or. S...

In cryptography, encryption is the process of encoding messages or information in such a way that only authorized parties can access it. Source: Encryption - Wikipedia

Imagine that we have a separate Google spreadsheet, and we need to get the B2 cell value to cell D5 on your current sheet. function copyValueandPaste() { var source = SpreadsheetApp.openById('spread sheet id is here'); //Separate spreadsheet book var sourcesheet = source.getSheetByName...

We can add Kendo-UI grid in HTML5/Javascript, ASP.NET MVC, JSP and PHP project/application. Please follow below steps to add kendo-UI grid in HTML5 page. Create empty html5 page. Include kendo.common.min.css and kendo.default.min.css. Add a link tag within the head tag. Kendo-UI li...

Consider the following naive method for adding two positive numbers using recursion: public static int add(int a, int b) { if (a == 0) { return b; } else { return add(a - 1, b + 1); // TAIL CALL } } This is algorithmically correct, but it has a major problem. ...

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For immutable elements (e.g. None, string literals etc.): my_list = [None] * 10 my_list = ['test'] * 10 For mutable elements, the same construct will result in all elements of the list referring to the same object, for example, for a set: >>> my_list=[{1}] * 10 >>> print(my_...

General syntax: DATEADD (datepart , number , datetime_expr) To add a time measure, the number must be positive. To subtract a time measure, the number must be negative. Examples DECLARE @now DATETIME2 = GETDATE(); SELECT @now; --2016-07-21 14:39:46.4170000 SELECT DAT...

These are the datepart values available to date & time functions: datepartAbbreviationsyearyy, yyyyquarterqq, qmonthmm, mdayofyeardy, ydaydd, dweekwk, wwweekdaydw, whourhhminutemi, nsecondss, smillisecondmsmicrosecondmcsnanosecondns NOTE: Use of abbreviations is generally discouraged as they c...

General syntax: DATEDIFF (datepart, datetime_expr1, datetime_expr2) It will return a positive number if datetime_expr is in the past relative to datetime_expr2, and a negative number otherwise. Examples DECLARE @now DATETIME2 = GETDATE(); DECLARE @oneYearAgo DATETIME2 = DATEADD(YEAR, -1, @now...

DATEPART returns the specified datepart of the specified datetime expression as a numeric value. DATENAME returns a character string that represents the specified datepart of the specified date. In practice DATENAME is mostly useful for getting the name of the month or the day of the week. There a...

Sometimes when destructuring maps, you would like to bind the destructured values to their respective key name. Depending on the granularity of the data structure, using the standard destructuring scheme may be a little bit verbose. Let's say, we have a map based record like so : (def john {:lastn...

One approach that is employed often is to use bootstrap's gridded framework in order to define the area that the chart will exist in. Using this in conjunction with clientWidth variable and the window.onresize event, it is very easy to create responsive d3 SVGs. Let's first create a row and a colum...

A CSS rule consists of a selector (e.g. h1) and declaration block ({}). h1 {}

Some properties can take multiple values, collectively known as a property list. /* Two values in this property list */ span { text-shadow: yellow 0 0 3px, green 4px 4px 10px; } /* Alternate Formatting */ span { text-shadow: yellow 0 0 3px, green 4px 4px 10px; } ...

This example shows how to create a table, insert data, and select from the database using the SQLAlchemy ORM. For information re: SQLAlchemy Core, see here. First things first, we need to connect to our database, which is identical to how we would connect using SQLAlchemy Core (Core). from sqlalch...

add_action( 'wp_enqueue_scripts', 'enqueue_my_styles_and_scripts' ); /** * Enqueue styles (or scripts) conditionally. * * Load stylesheets (or scripts) specifically for IE. IE10 and above does * not support conditional comments in standards mode. * * @link https://gist.github.com/wpsc...

@media print { p { page-break-inside: avoid; } h1 { page-break-before: always; } h2 { page-break-after: avoid; } } This code does 3 things: it prevents a page break inside any p tags, meaning a paragraph will never be broken in two pages, if possible. it for...