Tutorial by Examples: v

The function is_array() returns true if a variable is an array. $integer = 1337; $array = [1337, 42]; is_array($integer); // false is_array($array); // true You can type hint the array type in a function to enforce a parameter type; passing anything else will result in a fatal error. funct...

To use Vagrant on Windows platform you need to install virtualization software and an ssh command-line tool first. This example will use freeware VirtualBox and Cygwin. Install VirtualBox Download the latest VirtualBox version from the official download page and run the downloaded file. Note that ...

Classes in MATLAB are divided into two major categories: value classes and handle classes. The major difference is that when copying an instance of a value class, the underlying data is copied to the new instance, while for handle classes the new instance points to the original data and changing val...

Responding to Editing Notifications textViewShouldBeginEditing(_:) textViewDidBeginEditing(_:) textViewShouldEndEditing(_:) textViewDidEndEditing(_:) Responding to Text Changes textView(_:shouldChangeTextIn:replacementText:) textViewDidChange(_:) Responding to URL textView(_: UITe...

A Docker volume is a file or directory which persists beyond the lifetime of the container. It is possible to mount a host file or directory into a container as a volume (bypassing the UnionFS). Add a volume with the -v command line option: docker run -d -v "/data" awesome/app bootstrap....

You have started an interactive rebase. In the editor where you pick your commits, you decide that something is going wrong (for example a commit is missing, or you chose the wrong rebase destination), and you want to abort the rebase. To do this, simply delete all commits and actions (i.e. all lin...

Overview In order to debug Java classes that are called during MATLAB execution, it is necessary to perform two steps: Run MATLAB in JVM debugging mode. Attach a Java debugger to the MATLAB process. When MATLAB is started in JVM debugging mode, the following message appears in the command wi...

To jump back to a previous commit, first find the commit's hash using git log. To temporarily jump back to that commit, detach your head with: git checkout 789abcd This places you at commit 789abcd. You can now make new commits on top of this old commit without affecting the branch your head is...

To get a verbose list of all devices connected to adb, write the following command in your terminal: adb devices -l Example Output List of devices attached ZX1G425DC6 device usb:336592896X product:shamu model:Nexus_6 device:shamu 013e4e127e59a868 device usb:337641472X produc...

Write the following command in your terminal: adb shell getprop This will print all available information in the form of key/value pairs. You can just read specific information by appending the name of a specific key to the command. For example: adb shell getprop ro.product.model Here are a...

If you need to remove one or more elements from a slice, or if you need to work with a sub slice of another existing one; you can use the following method. Following examples uses slice of int, but that works with all type of slice. So for that, we need a slice, from witch we will remove some ...

ActionScript 3 can be used by installing the Adobe AIR SDK or Apache Flex SDK or as part Adobe's Animate CC product (formerly known as Flash Professional). Adobe Animate CC is a professional software solution that can be used to create AS3 projects using visual tools - once installed, no further st...

var object = { key1: 10, key2: 3, key3: 40, key4: 20 }; var array = []; for(var people in object) { array.push([people, object[people]]); } Now array is [ ["key1", 10], ["key2", 3], ["key3", 40], ["key4", 20] ] ...

To previous view controller To pop back to the previous page you can do this: Swift navigationController?.popViewControllerAnimated(true) Objective-C [self.navigationController popViewControllerAnimated:YES]; To root view controller To pop to the root of the navigation stack, you can do...

In your storyboard select the ViewController that you want to embed into a Navigation Controller. Then navigate to Editor > Embed In > Navigation Controller And that will create your navigation controller

You can use the Integer method to convert a String to an Integer: Integer("123") # => 123 Integer("0xFF") # => 255 Integer("0b100") # => 4 Integer("0555") # => 365 You can also pass a base parameter to the Integer method to c...

To run migrations in the test environment, run this shell command: rake db:migrate RAILS_ENV=test 5.0 Starting in Rails 5.0, you can use rails instead of rake: rails db:migrate RAILS_ENV=test

To remove existing column name from users table, run the command: rails generate migration RemoveNameFromUsers name:string This will generate the following migration: class RemoveNameFromUsers < ActiveRecord::Migration[5.0] def change remove_column :users, :name, :string end end ...

The services lifecycle has the following callbacks onCreate() : Executed when the service is first created in order to set up the initial configurations you might need. This method is executed only if the service is not already running. onStartCommand() : Executed every time startService...

You can create a new class that inherits from HashSet: Set<String> h = new HashSet<String>() {{ add("a"); add("b"); }}; One line solution: Set<String> h = new HashSet<String>(Arrays.asList("a", "b")); Using guava: Se...