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

eclipse plugin - Run java code error: Workspace is closed -

To create an automated project, I created a plug-in project with the following dependencies: Org.eclipse.core.resources org.eclipse.equinox.registry org.eclipse.core.runtime and the following The Java class is located in the src folder: Package Examiner; Import org.eclipse.core.resources.IProject; Import org.eclipse.core.resources.IWorkspaceRoot; Import org.eclipse.core.resources.ResourcesPlugin; Import org.eclipse.core.runtime.CoreException; Import org.eclipse.core.runtime.IProgressMonitor; Import org.eclipse.core.runtime.NullProgressMonitor; Public class tes {public static zero main (string [] args) {// TODO auto generated method stub IProgressMonitor progress monitor = new NullProgressMonitor (); IWorkspaceRoot root = ResourcesPlugin.getWorkspace (). GetRoot (); Ipoject project = root.jetproject ("desired projectname"); Try {Project.create (progress monitor); Project.open (progressMonitor); } Grip (CoreException E) {// TODO Auto generated blocking block e....
Read more

ios - How do I use CFArrayRef in Swift? -

I am using Objective-class in my Swift Project through a bridging header. The method signature looks like this: - Some cement (some type) some parameters; I started by getting an example of class, calling method, and storing the value: var myInstance = MyClassWithThatMethod (); Var cfArr = myInstance.someMethod (some value); Then try to get the value in the array: var valueInArrayThatIWant = CFArrayGetValueAtIndex (cfArr, 0); However, I get the error unmanaged & lt; Cfarray & gt; Not like 'CFArray' . Unmanaged & lt; Cfarray & gt; also means? I looked, but I do not need to change the array in a fast array (though it would be good). I need to be able to get value from the array. I also tried CFArray method to pass in a function: func doSomeStuffOnArray (myArray: NSArray) {} Although I get the same error when using: doSomeStuffOnArray (cfArr); // unmanaged & lt; CFArray & gt; I am using CFArray because I want to sto...
Read more

scala - Play Framework - how to bind form to a session field -

Is there any way, I can get some parameters from the header, cookies (log in userId in my case) , And then apply it in a form which I know who will deposit the ticket? SupportForm supportForm: form [supportTicket] = form (mapping ("question" -> text, "priority" -> text) (apply support ticket. (HelpText.update) What are the good practices here? What is the call to apply the request, when I can use it (and also a good practice?) Edit An issue, absolutely deceiving anyone if I were to create a hidden area with this value. It could Ript, but the issue may be re-used in any way to verify and return the form, it can not be sure how it ....
Read more