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A custom exception is any class that extends Exception or a subclass of Exception. In general, you should always extend StandardError or a descendant. The Exception family are usually for virtual-machine or system errors, rescuing them can prevent a forced interruption from working as expected. # ...

Use the begin/rescue block to catch (rescue) an exception and handle it: begin # an execution that may fail rescue # something to execute in case of failure end A rescue clause is analogous to a catch block in a curly brace language like C# or Java. A bare rescue like this rescues Stand...

You can handle multiple errors in the same rescue declaration: begin # an execution that may fail rescue FirstError, SecondError => e # do something if a FirstError or SecondError occurs end You can also add multiple rescue declarations: begin # an execution that may fail rescue ...

In order to exit Vim, first make sure you are in Normal mode by pressing Esc. :q Enter (will prevent you from exiting if you have unsaved changes - short for :quit) To discard changes and exit Vim: :q! Enter to force exit and discard changes (short for :quit!, not to be confused with :!q), ...

You can set the timezone that will be used by Django in the settings.py file. Examples: TIME_ZONE = 'UTC' # use this, whenever possible TIME_ZONE = 'Europe/Berlin' TIME_ZONE = 'Etc/GMT+1' Here is the list of valid timezones When running in a Windows environment this must be set to the same a...

Deploying an advanced project template to shared hosting is a bit trickier than a basic one because it has two webroots, which shared hosting webservers don't support. We will need to adjust the directory structure so frontend URL will be http://site.local and backend URL will be http://site.local/a...

A button can be disabled by Swift myButton.isEnabled = false Objective-C: myButton.enabled = NO; The button will become gray: If you don't want the button appearance to change when disabled set adjustsImageWhenDisabled to false / NO

Swift label.backgroundColor = UIColor.redColor() label.backgroundColor = .redColor() Swift 3 label.backgroundColor = UIColor.red Objective-C label.backgroundColor = [UIColor redColor];

Often we want to operate only on elements of an array that fulfill a specific condition: Select Will return elements that match a specific condition array = [1, 2, 3, 4, 5, 6] array.select { |number| number > 3 } # => [4, 5, 6] Reject Will return elements that do not match a specific c...

Suppose you have defined the following Person class: public class Person { String name; int age; public Person (int age, String name) { this.age = age; this.name = name; } } If you instantiate a new Person object: Person person = new Person(25, &qu...

Introduction SharePoint 2016 is the version 16 release of the SharePoint product family. It was released on May 4, 2016. This example covers the installation of SharePoint 2016 using the Single Server Farm configuration. This configuration covers the basics of setting up a SharePoint farm without t...

#include <stdlib.h> #include <lauxlib.h> #include <lua.h> #include <lualib.h> int main(void) { lua_State *lvm_hnd = lua_open(); luaL_openlibs(lvm_hnd); /* Load a standard Lua function from global table: */ lua_getglobal(lvm_hnd, "print&quot...

CommandDescription<Esc>Leaves insert mode, triggers autocommands and abbreviations<C-[>Exact synonymous of <Esc><C-c>Leaves insert mode, doesn't trigger autocommands Some people like to use a relatively uncommon pair of characters like jk as shortcut for <Esc> or <C...

There are many ways you can create a UIColor: Swift Using one of the predefined colors: let redColor = UIColor.redColor() let blueColor: UIColor = .blueColor() // In Swift 3, the "Color()" suffix is removed: let redColor = UIColor.red let blueColor: UIColor = .blue If the c...

File f = new File(path); String content = new Scanner(f).useDelimiter("\\Z").next(); \Z is the EOF (End of File) Symbol. When set as delimiter the Scanner will read the fill until the EOF Flag is reached.

Inline SVG allows SVG markup, written within HTML, to generate graphics in the browser. When using SVG inline, a DOCTYPE is not strictly required. Instead just the <svg> opening and closing tags together with either a viewBox or width and height attributes will suffice: <svg width="1...

Directives are one of the most powerful features of angularjs. Custom angularjs directives are used to extend functionality of html by creating new html elements or custom attributes to provide certain behavior to an html tag. directive.js // Create the App module if you haven't created it yet va...

If the items in your RecyclerView load data from the network (commonly images) or carry out other processing, that can take a significant amount of time and you may end up with items on-screen but not fully loaded. To avoid this you can extend the existing LinearLayoutManager to preload a number of...

This progam uses VCL, the default UI components library of Delphi, to print "Hello World" into a message box. The VCL wrapps most of the commonly used WinAPI components. This way, they can be used much easier, e.g. without the need to work with Window Handles. To include a dependency (lik...

There is already a function sum(). As a result, if we name a variable with the same name sum = 1+3; and if we try to use the function while the variable still exists in the workspace A = rand(2); sum(A,1) we will get the cryptic error: Subscript indices must either be real positive integer...