How to terminate the script in JavaScript

Question

How can I exit the JavaScript script much like PHP s exit or die  I know it s not the best programming practice but I need to

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This code will stop execution of all JavaScripts in current window   x000D   x000D      for      x000D   x000D   x000D

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There are many ways to exit a JS or Node script  Here are the most relevant      This will never exit  setInterval  function           return      5000       This will exit after 5 seconds  with signal 1 setTimeout  function           return process exit 1       5000       This will also exit after 5 seconds  and print its  killed  PID setTimeout  function           return process kill process pid       5000       This will also exit after 5 seconds and create a core dump  setTimeout  function           return process abort        5000     If you re in the REPL  i e  after running node on the command line   you can type  exit to exit

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throw      Is a misuse of the concept but probably the only option  And  yes  you will have to reset all event listeners  just like the accepted answer mentions  You would also need a single point of entry if I am right   On the top of it  You want a page which reports to you by email as soon as it throws - you can use for example Raven Sentry for this  But that means  you produce yourself false positives  In such case  you also need to update the default handler to filter such events out or set such events on ignore on Sentry s dashboard   window stop     This does not work during the loading of the page  It stops decoding of the page as well  So you cannot really use it to offer user a javascript-free variant of your page   debugger   Stops execution only with debugger opened  Works great  but not a deliverable

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Even in simple programs without handles  events and such  it is best to put code in a  main  function  even when it is the only procedure     lt script gt   function main       code    main     lt  script gt    This way  when you want to stop the program you can use  return

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i use this piece of code to stop execution    throw new FatalError     Stop JS         you will get a console error though but it works good for me

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This little function comes pretty close to mimicking PHP s exit    As with the other solutions  don t add anything else   function exit Msg            Msg Msg        Msg         if  Msg  alert Msg       throw new Error             exit

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If you just want to stop further code from executing without  throwing  any error  you can temporarily override window onerror as shown in cross-exit   function exit code        const prevOnError   window onerror     window onerror        gt            window onerror   prevOnError         return true            throw new Error  Script termination with code   code    0        console log  This message is logged     exit    console log  This message isn t logged

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If you use any undefined function in the script then script will stop due to  Uncaught ReferenceError   I have tried by following code and first two lines executed    I think  this is the best way to stop the script  If there s any other way then please comment me  I also want to know another best and simple way  BTW  I didn t get exit or  die inbuilt function in Javascript like PHP for terminate the script  If anyone know then please let me know   alert  Hello     document write  Hello User        die       Uncaught ReferenceError  die is not defined  alert  bye     document write  Bye User

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If you re looking for a way to forcibly terminate execution of all Javascript on a page  I m not sure there is an officially sanctioned way to do that - it seems like the kind of thing that might be a security risk  although to be honest  I can t think of how it would be off the top of my head   Normally in Javascript when you want your code to stop running  you just return from whatever function is executing   The return statement is optional if it s the last thing in the function and the function shouldn t return a value  If there s some reason returning isn t good enough for you  you should probably edit more detail into the question as to why you think you need it and perhaps someone can offer an alternate solution   Note that in practice  most browsers  Javascript interpreters will simply stop running the current script if they encounter an error  So you can do something like accessing an attribute of an unset variable   function exit         p blah        and it will probably abort the script  But you shouldn t count on that because it s not at all standard  and it really seems like a terrible practice   EDIT  OK  maybe this wasn t such a good answer in light of   lafur s  Although the die   function he linked to basically implements my second paragraph  i e  it just throws an error

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In JavaScript multiple ways are there  below are some of them  Method 1   throw new Error  Something went badly wrong       Method 2   return    Method 3   return false    Method 4   new new   Method 5   write your custom function use above method and call where you needed  Note  If you want to just pause the code execution you can use   debugger

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If you don t care that it s an error just write   fail    That will stop your main  global  code from proceeding  Useful for some aspects of debugging testing

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If you are using Firefox or a Browser it cannot be done with most of these Console methods once you have started an iterator   as you can see I have    You can go to source and manually pause the execution of the script    This still does not Stop it completely per say  Screenshot of Developer Mode

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i use return statement instead of throw as throw gives error in console  the best way to do it is to check the condition   if condition    return   whatever you want to return     this simply stops the execution of the program from that line  instead of giving any errors in the console

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This is an example  that  if a condition exist  then terminate the script  I use this in my SSE client side javascript  if the    lt script src  sse-clint js  host  https   sse host  query    q1  q2     gt  lt  script gt    canot be parsed right from JSON parse      if    SSE HOST    throw new Error       SSE js  ERR NOHOST - finished             anyway the general idea is   if  error  true  throw new Error    You have This error      At this file    At this line         this will terminate die your javasript script

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I know this is old  but if you want a similar PHP die   function  you could do  function die reason        throw new Error reason      Usage  console log  quot Hello quot    die  quot Exiting script    quot       Kills script right here console log  quot World  quot     The example above will only print  quot Hello quot

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exit  functions usually quit the program or script along with an error message as paramete  For example die      in php   die  sorry my fault  didn t mean to but now I am in byte nirvana     The equivalent in JS is to signal an error with the throw keyword like this   throw new Error      You can easily test this   var m   100  throw     var x   100   x  gt  gt  gt undefined m  gt  gt  gt 100

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Simply create a BOOL condition   no need for complicated code here    If even once you turn it to true  or multiple times  it will both give you one line of solution not multiple - basically simple as  that

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I think this question has been answered  click here for more information  Below is the short answer it is posted   throw new Error  Stop script      You can also used your browser to add break points  every browser is similar  check info below for your browser   For Chrome break points info click here For Firefox break    points info click here For Explorer break points info click For Safari break points info click here

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Not applicable in most circumstances  but I had lots of async scripts running in the browser and as a hack I do  window reload      to stop everything

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In my case I used the window stop API which is like clicking the X button on your browser   window stop

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JavaScript equivalent for PHP s die  BTW it just calls exit    thanks splattne    function exit  status            http   kevin vanzonneveld net            original by  Brett Zamir  http   brettz9 blogspot com                input by  Paul            bugfixed by  Hyam Singer  http   www impact-computing com              improved by  Philip Peterson            bugfixed by  Brett Zamir  http   brettz9 blogspot com                  note 1  Should be considered expirimental  Please comment on this function               example 1  exit                 returns 1  null      var i       if  typeof status      string             alert status              window addEventListener  error   function  e   e preventDefault   e stopPropagation      false        var handlers              copy    cut    paste            beforeunload    blur    change    click    contextmenu    dblclick    focus    keydown    keypress    keyup    mousedown    mousemove    mouseout    mouseover    mouseup    resize    scroll            DOMNodeInserted    DOMNodeRemoved    DOMNodeRemovedFromDocument    DOMNodeInsertedIntoDocument    DOMAttrModified    DOMCharacterDataModified    DOMElementNameChanged    DOMAttributeNameChanged    DOMActivate    DOMFocusIn    DOMFocusOut    online    offline    textInput            abort    close    dragdrop    load    paint    reset    select    submit    unload              function stopPropagation  e            e stopPropagation               e preventDefault       Stop for the form controls  etc   too            for  i 0  i  lt  handlers length  i              window addEventListener handlers i   function  e   stopPropagation e     true              if  window stop            window stop               throw

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I am using iobroker and easily managed to stop the script with  stopScript

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Place the debugger  keyword in your JavaScript code where you want to stop the execution  Then open your favorite browser s developer tools and reload the page  Now it should pause automatically  Open the Sources section of your tools  the debugger  keyword is highlighted and you have the option to resume script execution   I hope it helps   More information at    https   developer mozilla org de docs Tools Debugger http   www w3schools com js js debugging asp

[javascript] How to terminate the script in JavaScript?

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