Early exit from function

Question

I have a function   function myfunction       if  a     stop       How can I stop the function here      Is there something like exit   in JavaScript

User · Answer

Using a little different approach  you can use try catch  with throw statement   function name         try                          get out of here         if  a     stop               throw  exit                      catch  e               TODO  handle exception

User · Answer

type any random command that throws an error  for example   exit   or   die -

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This   function myfunction          if  a     stop       How can I stop working of function here                  return

User · Answer

Apparently you can do this   function myFunction    myFunction       console log  i get executed        break myFunction      console log  i do not get executed         See block scopes through the use of a label  https   developer mozilla org en-US docs Web JavaScript Reference Statements label  I can t see any downsides yet  But it doesn t seem like a common use   Derived this answer  JavaScript equivalent of PHP   s die

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I dislike answering things that aren t a real solution        but when I encountered this same problem  I made below workaround   function doThis       var err 0   if  cond1    alert  ret1    err 1      if  cond2    alert  ret2    err 1      if  cond3    alert  ret3    err 1      if  err  lt  1           do the rest  or have it skipped          Hope it can be useful for anyone

User · Answer

You can just use return   function myfunction          if a     stop             return      This will send a return value of undefined to whatever called the function   var x   myfunction     console log  x        console shows undefined   Of course  you can specify a different return value  Whatever value is returned will be logged to the console using the above example   return false  return true  return  some string   return 12345

User · Answer

exit    can be use to go for the next validation

User · Answer

Using a return will stop the function and return undefined  or the value that you specify with the return command   function myfunction        if a   stop              return undefined          return      Or return  Hello  or any other value

User · Answer

function myfunction          if a     stop             return false      return false  is much better than just return

User · Answer

I think throw a new error is good approach to stop execution rather than just return or return false  For ex  I am validating a number of files that I only allow max five files for upload in separate function   validateMaxNumber  function length       if  5  gt   length               Continue execution            Flash error message and stop execution       Can t stop execution by return or return false statement      let message    No more than     this maxNumber     File is allowed      throw new Error message       But I am calling this function from main flow function as    handleFilesUpload           let files    document getElementById  myFile   files        this validateMaxNumber files length       In the above example I can t stop execution unless I throw new Error Just return or return false only works if you are in main function of execution otherwise it doesn t work

User · Answer

If you are using jquery   This should stop the function from bubbling up to so the parent function calling this should stop as well     function myfunction e             e stopImmediatePropagation

User · Answer

if you are looking for a script to avoid submitting form when some errors found  this method should work  function verifyData         if  document MyForm FormInput value length                    alert  Write something                 else             document MyForm submit               change the Submit Button type to  button    lt input value  Save  type  button  onClick  verifyData    gt    hope this help

[javascript] Early exit from function?

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