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Java equivalent to #region in C#

I want to use regions for code folding in Eclipse; how can that be done in Java?

An example usage in C#:

#region name
//code
#endregion
I joined the party late. I agree with IKashef that there are other options that the current selected answer. The answer of Yaqub Ahmad saved my life. I didn't need to download the Intellig IDE. I downloaded the mentioned CoffeeBytes plugin from the comment of cking24343, I applied the configuration of 'null n void' and worked well in Luna. You need to restart after applying the configuration
start with //region [Description] and end with //endregion
later and not specifically Java, but related for Eclipse folding: stackoverflow.com/q/13505413/7224691

A
Alexander Bezrodniy

Jet Brains IDEA has this feature. You can use hotkey surround with for that (ctrl + alt + T). It's just IDEA feature.

Regions there look like this:

//region Description

Some code

//endregion

Thanks for that! Works perfectly on Android Studio.
The question clearly requests a solution for Eclipse.
@Duncan 1. Nothing wrong to show people there are alternatives. 2. I google for regions under Intellij and found it.
On Linux, that hotkey runs terminal
Just tried it and it seems like IntelliJ supports nested regions as well! Too bad this is not standard.
B
Brian Agnew

There's no such standard equivalent. Some IDEs - Intellij, for instance, or Eclipse - can fold depending on the code types involved (constructors, imports etc.), but there's nothing quite like #region.


Actually this can be achieved. If you scroll down on this post "Yaqub Ahmad" explains how to get this functionality. Also here is a link (kosiara87.blogspot.com/2011/12/…) that shows you how to add it to your existing eclipse environment...extremely useful!
Sure. But there's nothing standard. It's performed in IDEs rather than having a language (or text) construct
@lKashef - so what's the standard equivalent then ? Everything noted below relates to a particular IDE, doesn't it ?
@BrianAgnew, The OP didn't mention anything about standards instead he just want to be able to have regions-like blocks in his code. For instance you said "but there's nothing quite like #region." in IDEA for example //region .. //endregion works exactly like #region. There's no standard way of doing this at all in the first place since it depends on the IDE itself or a plugin. Developers with microsoft backgrounds will always see MS Visual Studio as "The" IDE but in fact it's just one of the options and another IDE might or might not implement such functionality.
@BrianAgnew, I almost gave up until I saw other people's answers which helped more than yours. Seriously no hard feeling here, We are all here to learn and share our knowledge and am stating the fact that I was mislead by your answer, maybe it was a good one back in 2010 but not today. I hope you get my point.
b
bummi

With Android Studio, try this:

//region VARIABLES
private String _sMyVar1;
private String _sMyVar2;
//endregion

Careful : no blank line after //region ...

And you will get:

https://i.stack.imgur.com/2MarZ.png


was going through all answers and figured since Android Studio is based on IntelliJ then this must be supported. good thing to point it out though!
bummi, I did try it in 0.4.2 with a blank line and still works
Just a comment/advice (and by no means an answer to your question). It is a widespread opinion that regions should be avoided, since they let you hide class complexity instead of working on your coding style. Instead of huge classes, where each class is responsible for a lot of functionality, work on breaking down your code into smaller classes instead. It will make your code easier to manage over time. Read more here: blog.codinghorror.com/the-problem-with-code-folding
@DanielSaidi oh, the horror! :) the guy in the article "I can't see anything! I have to manually expand those sections to browse any of the code in this class." ... so because he's too lazy to press a key (that woulld expand all sections in the file), the feature must not be used - it's a super wonderful feature. Right now I'm using it to one by one hide the methods I've verified are thread safe in the class I'm working one, it really helps to keep organized.Sure once in a while I've wondered where something is that I thought was there, but that is a small price to pay...
@DanielSaidi It's not about hiding complexity but hiding mundane code such as variable declarations, getters, initialization code and so on. Also note that you DO NOT require #regions to collapse the "complex code" found in functions and classes. The beef with programmers using a tool incorrectly does not amount to "the tool is bad".
K
Kevin LaBranche

No equivalent in the language... Based on IDEs...

For example in netbeans:

NetBeans/Creator supports this syntax:

// <editor-fold defaultstate="collapsed" desc="Your Fold Comment">
...
// </editor-fold>

http://forums.java.net/jive/thread.jspa?threadID=1311


Even though it's not a language specific folding but still helped me in NetBeans. Exactly what I wanted to achieve. Just want my code to be more handy and organized for me.
Is there any shortcut that can auto fill this line?
@pini-cheyni - ui.netbeans.org/docs/ui/code_folding/cf_uispec.html has shortcuts available for folding....
@JadChahine: The OP asked about Eclipse, but agree this works well for NetBeans. Syntax is a slightly clumsy but copy-paste makes it easy enough.
M
Michieru

Custom code folding feature can be added to eclipse using CoffeeScript code folding plugin.

This is tested to work with eclipse Luna and Juno. Here are the steps

Download the plugin from here Extract the contents of archive Copy paste the contents of plugin and features folder to the same named folder inside eclipse installation directory Restart the eclipse Navigate Window >Preferences >Java >Editor >Folding >Select folding to use: Coffee Bytes Java >General tab >Tick checkboxes in front of User Defined Fold Create new region as shown: Restart the Eclipse. Try out if folding works with comments prefixed with specified starting and ending identifiers

You can download archive and find steps at this Blog also.


not working for me on eclipse neon: copy and paste did nothing: the only thing that changed was under marketplace >> installed plugins >>update. I updated the coffeeScript plugin, but I didn't get the option "Select folding to use" under java>> editor >> folding
It worked in the Eclipse Oxygen, however you need to restart the eclipse again. The icon displayed to me was a red icon so I changed in the configuration, Window → Preference → Java → Editor → Folding click at Advanced tab and change the Icon theme set to Modern
C
Community

For Eclipse IDE the Coffee-Bytes plugin can do it, download link is here.

EDIT:

Latest information about Coffee-Bytes is here.


+1 thanks for this info. Since the original website of the developper of the plugin is no longer available in 2012 - i found a short desctription for installation and usage.
anyone found an intelliJ alternative?
The download link does no longer exist.
h
heavyd

This is more of an IDE feature than a language feature. Netbeans allows you to define your own folding definitions using the following definition:

// <editor-fold defaultstate="collapsed" desc="user-description">
  ...any code...
// </editor-fold>

As noted in the article, this may be supported by other editors too, but there are no guarantees.


In Android studio, at least, you cannot fold part of a block. If the fold spec starts outside of a block, and ends inside a block, it will not activate.
y
ycomp

the fastest way in Android Studio (or IntelliJ IDEA)

highlight the code you want to surround it press ctrl + alt + t press c ==> then enter the description enjoy


// region Your code... // endregion Is more efficient and simple! hehe ;P
L
Linh

AndroidStudio region
Create region

https://i.stack.imgur.com/zyRLd.png

https://i.stack.imgur.com/N1EJn.gif

Go to region

https://i.stack.imgur.com/JyATQ.png


J
Johann

Contrary to what most are posting, this is NOT an IDE thing. It is a language thing. The #region is a C# statement.


What most are posting is that IN JAVA this is an IDE feature.
I do see the 2 most popular answers saying there is no such language feature. -1.
In C# it is partly IDE, partly language. The language supports the preprocessor directives, but the preprocessor simply ignores them (the same way processor ignores comments). The IDE (Visual Studio) uses them to do code folding.
Java doesn't has specified code folding only the IDE (Netbeans) has, Netbeans has more special comments like "TODO" and more. They are very useful to track your progress through SW project development process
A
Amir Ziarati

I were coming from C# to java and had the same problem and the best and exact alternative for region is something like below (working in Android Studio, dont know about intelliJ):

 //region [Description]
 int a;
 int b;
 int c;
//endregion

the shortcut is like below:

1- select the code

2- press ctrl + alt + t

3- press c and write your description


In AndroidStudio version 2.3.1 it folds. I don't know when it started to fold.
Thanks. Works perfectly in Android Studio 3.0 beta 2. By curiosity I tried in Eclipse Oxygen, it doesn't work by default but didn't search further.
T
Taddeo

The best way

//region DESCRIPTION_REGION
int x = 22;
// Comments
String s = "SomeString";
//endregion;

Tip: Put ";" at the end of the "endregion"


eclipse do not fold the code, what IDE are u using?
It works with Android Studio and IntelliJ IDEA (both are made from same codebase by JetBrains)
R
Ricky

If anyone is interested, in Eclipse you can collapse all your methods etc in one go, just right click when you'd normally insert a break point, click 'Folding' > 'Collapse all'. It know it's not an answer to the question, but just providing an alternative to quick code folding.


You can also have Eclipse auto-collapse everything when opening a source code file. Preferences > Java > Editor > Folding > "Initially fold these elements" (check all in the list). I find it convenient to focus on only what I need especially in long source code files.
@ADTC - Thanks - so many hundreds of times I've done it manually every time I open a file - never again!!
@ToolmakerSteve If you can do anything repetitive manually on a computer, there just has to be a way to automate it. =D
C
Coder123

here is an example:

//region regionName
//code
//endregion

100% works in Android studio


I don't know why you have been downvoted, this actually works in Android Studio without any configuration needed!
J
Justin Niessner
#region

// code

#endregion

Really only gets you any benefit in the IDE. With Java, there's no set standard in IDE, so there's really no standard parallel to #region.


Well if there's a standard to region, then we can be sure that java IDE's will support it isn't it?
@Pacerier if they support that standard, yes. I think #region is more an IDE feature than a standard. In theory the java IDE's could implement this behavior and make it a de-facto standard
Y
Yawar

I usually need this for commented code so I use curly brackets at start and end of that.

{
// Code
// Code
// Code
// Code
}

It could be used for code snippets but can create problems in some code because it changes the scope of variable.


S
Solarcloud

vscode

I use vscode for java and it works pretty much the same as visual studio except you use comments:

//#region name

//code

//#endregion

https://i.stack.imgur.com/kBpwp.png


G
George

Meet custom folding regions ⌥⌘T

https://i.stack.imgur.com/azcIG.gif


r
rmrrm

Actually johann, the # indicates that it's a preprocessor directive, which basically means it tells the IDE what to do.

In the case of using #region and #endregion in your code, it makes NO difference in the final code whether it's there or not. Can you really call it a language element if using it changes nothing?

Apart from that, java doesn't have preprocessor directives, which means the option of code folding is defined on a per-ide basis, in netbeans for example with a //< code-fold> statement


can you really call it a language element if using it changes nothing? - how about comments ?!
I've hear the argument before that it isn't a function of the language. And this question "Can you really call it a language element if using it changes nothing?" is ridiculous. A lot of time refactoring is making the code easier to read for humans and does nothing (hopefully) to impact the function of the code.
V
Victor Ruiz.

On Mac and Android Studio follow this sequence:

Highlight the source code to fold Press Alt+Command+t Select

Also you can select other options:

https://i.stack.imgur.com/OQJo1.png


M
Madhav Balakrishnan Nair

In Visual Studio Code, try this:

//region Variables
// Code you need
//endregion

j
j0k

In Eclipse you can collapse the brackets wrapping variable region block. The closest is to do something like this:

public class counter_class 
{ 

    { // Region

        int variable = 0;

    }
}

This is useless. It doesn't work inside a method, plus it BREAKS CODE! (Private variables will complain they want to be final. Variable with no scope definition will not be accessible outside the inner brackets!)
I don't like this method, adds too many curly braces. This can lead to confusing code :(
a
acmoune

Just intall and enable Coffee-Bytes plugin (Eclipse)


Not only is this mentioned in an earlier answer, but you didn't even provide any useful information about it.
A
Abhishek

There is some option to achieve the same, Follow the below points.

1) Open Macro explorer:

2) Create new macro:

3) Name it "OutlineRegions" (Or whatever you want)

4) Right Click on the "OutlineRegions" (Showing on Macro Explorer) select the "Edit" option and paste the following VB code into it:

    Imports System
Imports EnvDTE
Imports EnvDTE80
Imports EnvDTE90
Imports EnvDTE90a
Imports EnvDTE100
Imports System.Diagnostics
Imports System.Collections

Public Module OutlineRegions

    Sub OutlineRegions()
        Dim selection As EnvDTE.TextSelection = DTE.ActiveDocument.Selection

        Const REGION_START As String = "//#region"
        Const REGION_END As String = "//#endregion"

        selection.SelectAll()
        Dim text As String = selection.Text
        selection.StartOfDocument(True)

        Dim startIndex As Integer
        Dim endIndex As Integer
        Dim lastIndex As Integer = 0
        Dim startRegions As Stack = New Stack()

        Do
            startIndex = text.IndexOf(REGION_START, lastIndex)
            endIndex = text.IndexOf(REGION_END, lastIndex)

            If startIndex = -1 AndAlso endIndex = -1 Then
                Exit Do
            End If

            If startIndex <> -1 AndAlso startIndex < endIndex Then
                startRegions.Push(startIndex)
                lastIndex = startIndex + 1
            Else
                ' Outline region ...
                selection.MoveToLineAndOffset(CalcLineNumber(text, CInt(startRegions.Pop())), 1)
                selection.MoveToLineAndOffset(CalcLineNumber(text, endIndex) + 1, 1, True)
                selection.OutlineSection()

                lastIndex = endIndex + 1
            End If
        Loop

        selection.StartOfDocument()
    End Sub

    Private Function CalcLineNumber(ByVal text As String, ByVal index As Integer)
        Dim lineNumber As Integer = 1
        Dim i As Integer = 0

        While i < index
            If text.Chars(i) = vbCr Then
                lineNumber += 1
                i += 1
            End If

            i += 1
        End While

        Return lineNumber
    End Function
End Module

5) Save the macro and close the editor.

6) Now let's assign shortcut to the macro. Go to Tools->Options->Environment->Keyboard and search for your macro in "show commands containing" textbox (Type: Macro into the text box, it will suggest the macros name, choose yours one.)

7) now in textbox under the "Press shortcut keys" you can enter the desired shortcut. I use Ctrl+M+N.

Use:

return
{
//Properties
//#region
Name:null,
Address:null
//#endregion
}

8) Press the saved shortcut key

See below result:

https://i.stack.imgur.com/c8gtK.png


Where is the Macro Explorer ? I am using Eclipse 4.3.1 and can't find it .
This is not even Java?
@CJBS - re: This code seems to be for Visual Basic.NET which would suggest the IDE is Visual Studio.
@JesseChisholm - that was my point. The OP wants Java, not VB, and is targeting the Eclipse IDE, not VS.
RIP answer. If he was using visual studio, he could have just used #region and #endregion