Tutorial by Examples: ed

Some experimental packages are not included in the METADATA package repository. These packages can be installed by directly cloning their Git repositories. Note that there may be dependencies of unregistered packages that are themselves unregistered; those dependencies cannot be resolved by the pack...

NSArray *aryFName = @[ @"Alice", @"Bob", @"Charlie", @"Quentin" ]; NSArray *aryLName = @[ @"Smith", @"Jones", @"Smith", @"Alberts" ]; NSArray *aryAge = @[ @24, @27, @33, @31 ]; //Create a Custom class with prope...

Without replacement With combn, each vector appears in a column: combn(LETTERS, 3) # Showing only first 10. [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10] [1,] "A" "A" "A" "A" "A" "A" "A" "A" &quo...

Without replacement choose(length(LETTERS), 5) [1] 65780 With replacement length(letters)^5 [1] 11881376

Use the following commands to create bookmarks and access bookmarks from within Emacs. Let us say that you are editing a file called foobar.org and suppose that you visit this file frequently to edit / view contents. It would be convenient to access this file with couple of key strokes rather than...

The EditText is the standard text entry widget in Android apps. If the user needs to enter text into an app, this is the primary way for them to do that. EditText There are many important properties that can be set to customize the behavior of an EditText. Several of these are listed below. Check ...

Nested list comprehensions, unlike list comprehensions with nested loops, are List comprehensions within a list comprehension. The initial expression can be any arbitrary expression, including another list comprehension. #List Comprehension with nested loop [x + y for x in [1, 2, 3] for y in [3, 4...

An F() object represents the value of a model field or annotated column. It makes it possible to refer to model field values and perform database operations using them without actually having to pull them out of the database into Python memory. - F() expressions It is appropriate to use F() obj...

This uses the SwiftyDropbox library to upload a file from a NSFileHandle to the Dropbox account using upload sessions, handling every error case: import UIKit import SwiftyDropbox class ViewController: UIViewController { // filled in later in doUpload: var fileHandle : NSFileHandle?...

Use the double negation syntax to check for truthiness of values. All values correspond to a boolean, irrespective of their type. irb(main):001:0> !!1234 => true irb(main):002:0> !!"Hello, world!" (irb):2: warning: string literal in condition => true irb(main):003:0> !...

You do not need to use double negation in if-else statements. if 'hello' puts 'hey!' else puts 'bye!' end The above code prints 'hey!' on the screen.

If you can say “YAGNI” (You ain’t gonna need it) about a feature, you better not implement it. There can be a lot of development time saved through focussing onto simplicity. Implementing such features anyway can lead to problems: Problems Overengineering If a product is more complicated than it...

You may want to re-seed your database without affecting your previously created seeds. For this purpose, you can use firstOrCreate in your seeder: EmployeeType::firstOrCreate([ 'type' => 'manager', ]); Then you can seed the database: php artisan db:seed Later, if you want to add a...

Method 1: proc sql; create table foo like sashelp.class; quit; Method 2: proc sql; create table bar as select * from sashelp.class (obs=0); quit; Method 1 should be the preferred option

val isOfAllowedAge = { user: User -> user.age > MINIMUM_AGE } val allowedUsers = users.filter(isOfAllowedAge)

The sample content used here is Tears of Steel, by Blender Foundation. Specifically, we will use the download titled "HD 720p (~365MB, mov, 2.0)". This is a single file that ends with the extension "mov" and will play in just about any modern media player. Note that the download...

I.Overview A significant difference between MongoDB & RDBMS is MongoDB has many kinds of operators. One of them is update operator, which is used in update statements. II.What happen if we don't use update operators? Suppose we have a student collection to store student information(Table view...

By default, all the controllers you generate with Symfony's built-in generate:controller command will make use of Symfony annotations for routing: namespace AppBundle\Controller; // You have to add a use statement for the annotation use Sensio\Bundle\FrameworkExtraBundle\Configuration\Route; ...

JSON is a very strict format (see http://json.org). That makes it easy to parse and write for machines but surprises humans when an inconspicuous mistakes breaks the document. Common Problems Trailing Comma Unlike most programming languages your are not allowed to add a trailing comma: { a: 1...

Ionic has some CSS components where you can use Ionicons as a default which have preset styling. The range class in the item <div> will apply correct styling to both the input and the icons inside it. Here's an example of a range slider. <div class="item range"> <i class...