java - How does having a final variable in a foreach loop work -


कोड के इस भाग पर विचार करें 

  सार्वजनिक स्थिर शून्य मुख्य (स्ट्रिंग [] args) { के लिए (अंतिम स्ट्रिंग्स: arrays.asList ("a", "b", "c")) {System.out.println (s); }}

यह कोड किसी विशिष्ट उद्देश्य की पूर्ति नहीं करता है, लेकिन अंतिम foreach-loop चर का उपयोग प्रदर्शित करता है।

यह कैसे काम करता है? एक एकल चर कैसे अंतिम हो सकता है, लेकिन इसे प्रत्येक लूप के साथ एक अलग मान निर्दिष्ट किया जाता है। या क्या इस चर को विभिन्न स्कोप / स्टैक में कई बार घोषित किया गया है?

यह जावा भाषा विशिष्टता में समझाया गया है (JLS),:

बयान के लिए बढ़ाया रूप है: 

  EnhancedForStatement: के लिए (FormalParameter: अभिव्यक्ति) वक्तव्य FormalParameter: VariableModifiers_opt प्रकार VariableDeclaratorId VariableDeclaratorId: पहचानकर्ता VariableDeclaratorId []

...

बयान के लिए बढ़ाया प्रपत्र के बयान के लिए एक मूल के बराबर है: 

  के लिए (I #i = अभिव्यक्ति। निषेध (); # i.has अगला ();) {VariableModifiers_opt TargetType Identifier = (TargetType) # i.next (); वक्तव्य}

इस प्रकार, पहचानकर्ता पाश से प्रत्येक यात्रा पर redeclared है।


Comments

Post a Comment

Popular posts from this blog

javascript - How to use the code plugin with popcornjs -

I'm making my first move with popcornes and I'm trying to use it, but to make sure Not to do this I gave an example, and found the video to play, but I can not use the plugin index.html: & lt; Script src = "bower_components / popcornjs / popcorn.js" & gt; & Lt; / Script & gt; & Lt; Script src = "bower_components / popcornjs / wrappers / common / popcorn.mediaElementProto.js" & gt; & Lt; / Script & gt; & Lt; Script src = "bower_components / popcornjs / wrappers / youtube / popcorn.HTMLYouTubeVideoElement.js" & gt; & Lt; / Script & gt; & Lt; Script src = "bower_components / popcornjs / plugins / code / popcorn.code.js" & gt; & Lt; / Script & gt; Media.js $ scope.player = popcorn.HTMLYouTubeVideoElement ("#media-player"); $ Scope.player src = "http://www.youtube.com/watch?v=DaN2Y2-wNSs"; // The following lines failed // $ scope.player.c...
Read more

python - rpy2 import is not working -

When I try to import rpy2, I get an error. Here is the code and error & gt; & Gt; & Gt; Import Traceback (Most Recent Call Final): File "C: \ PF \ WinPython-64bit-3.3.3.3 \ python-3.3.3.amd64 \ lib \ site-packages \ IPython \ core \ interactiveshell.py", line 2828 In the file, "ipython-input-148-c258a0f70d44" gt; Row 1, & lt; modules & gt; Import pandas.rpy.common file in runcode ajl (code_obj, self.user_global_ns, self.user_ns) file " C: \ PF \ WinPython-64bit-3.3.3.3 \ python-3.3.3.amd64 \ lib \ site-packages \ pandas \ rpy \ common.py ", line 14, in & lt; modules & gt; Rpy2.robjects .packages Import Import Import Import: A module name 'rpy2' What could be the problem? I Python Version 3.3.3 and PANDAS Version 0.13.1 Edit Tried to install rpy2 separately I get an error using python setup.py install which is not the module popen3 in OS . Running the site of Christophe Gohalke properly insta...
Read more

Python, converting png to gif using ImageMagick -

I am using Python 2.7.6, I had a problem converting some PNG files into GIF (an animation To create) os.system ("Convert-dated 1-Digiage background + page" + str (output_dir) + "/*.png -loop 0" + str (output_dir) + "/ Animation GIF") This was the error on which I have Parametre non welde - 1 Enough to go Without error, this is only an estimate, but ... If there is an empty space or quote in output_dir or other special characters, to avoid or quote you Nothing is doing, so your command line will look something like this: Convert - Day 1-digest background + page ~ / My image / *. Png -loop 0 ~ / My Photos / Animation.gif There may be a completely valid argument for sending ~ / my for input, and Pictures / *. PNG is to solve a full bank Additional relative path that converts is ready to deal with additional inputs, but then you have to ~ / My , which is not valid because it has something similar to the input, and some additio...
Read more