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

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"

<input value="Save" type="button" onClick="verifyData()">

hope this help.

User · Answer

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

User · Answer

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

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

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

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

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

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

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

exit    can be use to go for the next validation

User · Answer

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

[javascript] Early exit from function?

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