Is there any way to call a function periodically in JavaScript

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function test      alert  called       var id   setInterval  test      10000     call test every 10 seconds  function stop        call this to stop your interval     clearInterval id

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The native way is indeed setInterval   clearInterval    but if you are already using the Prototype library you can take advantage of PeriodicalExecutor   new PeriodicalUpdator myEvent  seconds     This prevents overlapping calls   From http   www prototypejs org api periodicalExecuter       it shields you against multiple parallel executions of the callback function  should it take longer than the given interval to execute  it maintains an internal    running    flag  which is shielded against exceptions in the callback function   This is especially useful if you use one to interact with the user at given intervals  e g  use a prompt or confirm call   this will avoid multiple message boxes all waiting to be actioned

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yes - take a look at setInterval and setTimeout for executing code at certain times  setInterval would be the one to use to execute code periodically   See a demo and answer here for usage

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The setInterval   method  repeatedly calls a function or executes a code snippet  with a fixed time delay between each call  It returns an interval ID which uniquely identifies the interval  so you can remove it later by calling clearInterval     var intervalId   setInterval function       alert  quot Interval reached every 5s quot      5000       You can clear a periodic function by uncommenting     clearInterval intervalId    See more   setInterval     MDN Web Docs

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Since you want the function to be executed periodically  use setInterval

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Everyone has a setTimeout setInterval solution already   I think that it is important to note that you can pass functions to setInterval  not just strings   Its actually probably a little  safer  to pass real functions instead of strings that will be  evaled  to those functions      example 1 function test       alert  called      var interval   setInterval test  10000     Or      example 2 var counter   0  var interval   setInterval function     alert     counter        5000

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Old question but   I also needed a periodical task runner and wrote TaskTimer  This is also useful when you need to run multiple tasks on different intervals     Timer with 1000ms  1 second  base interval resolution  const timer   new TaskTimer 1000       Add task s  based on tick intervals  timer add       id   job1            unique id of the task     tickInterval  5        run every 5 ticks  5 x interval   5000 ms      totalRuns  10          run 10 times only   set to 0 for unlimited times      callback task               code to be executed on each run         console log task id     task has run     task currentRuns     times                   Start the timer timer start     TaskTimer works both in browser and Node  See documentation for all features

User · Answer

You will want to have a look at setInterval   and setTimeout     Here is a decent tutorial article

User · Answer

Please note that setInterval   is often not the best solution for periodic execution - It really depends on what javascript you re actually calling periodically    eg  If you use setInterval   with a period of 1000ms and in the periodic function you make an ajax call that occasionally takes 2 seconds to return you will be making another ajax call before the first response gets back  This is usually undesirable   Many libraries have periodic methods that protect against the pitfalls of using setInterval naively such as the Prototype example given by Nelson   To achieve more robust periodic execution with a function that has a jQuery ajax call in it  consider something like this   function myPeriodicMethod         ajax       url            success  function data                         complete  function              schedule the next request  only  when the current one is complete        setTimeout myPeriodicMethod  1000                     schedule the first invocation  setTimeout myPeriodicMethod  1000     Another approach is to use setTimeout but track elapsed time in a variable and then set the timeout delay on each invocation dynamically to execute a function as close to the desired interval as possible but never faster than you can get responses back

[javascript] Is there any way to call a function periodically in JavaScript?

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