How do I call a dynamically-named method in Javascript

Question

I am working on dynamically creating some JavaScript that will be inserted into a web page as it s being constructed    The JavaScript will be used to populate a listbox based on the selection in another listbox  When the selection of one listbox is changed it will call a method name based on the selected value of the listbox   For example   Listbox1 contains    Colours Shapes   If Colours is selected then it will call a populate Colours method that populates another listbox     To clarify my question  How do I make that populate Colours call in JavaScript

User · Answer

Here is a working and simple solution for checking existence of a function and triaging that function dynamically by another function;

Trigger function

function runDynmicFunction(functionname){ 

    if (typeof window[functionname] == "function"  ) { //check availability

        window[functionname]("this is from the function it "); //run function and pass a parameter to it
    }
}

and you can now generate the function dynamically maybe using php like this

function runThis_func(my_Parameter){

    alert(my_Parameter +" triggerd");
}

now you can call the function using dynamically generated event

<?php

$name_frm_somware ="runThis_func";

echo "<input type='button' value='Button' onclick='runDynmicFunction(\"".$name_frm_somware."\");'>";

?>

the exact HTML code you need is

<input type="button" value="Button" onclick="runDynmicFunction('runThis_func');">

User · Answer

I wouldn t recommend using the window as some of the other answers suggest  Use this and scope accordingly   this  yourDynamicFcnName   arguments     Another neat trick is calling within different scopes and using it for inheritance  Let s say you had nested the function and want access to the global window object  You could do this   this  yourDynamicFcnName   call window  arguments

User · Answer

Try These Call Functions With Dynamic Names  like this  let dynamic func name    alert    new Function dynamic func name           with parameters  let dynamic func name    alert   let para 1    HAHAHA   let para 2    ABCD    new Function    dynamic func name     para 1      para 2          Run Dynamic Code  let some code    quot alert  hahaha    quot    new Function some code

User · Answer

A simple function to call a function dynamically with parameters  this callFunction   this call function   function name        var args   Array prototype slice call arguments  1       return window name  call this     args       function sayHello name  age        console log  hello     name      your  e age is     age       return some     console log call function  sayHello    john   30       hello john  your e age is 30

User · Answer

As Triptych points out  you can call any global scope function by finding it in the host object s contents   A cleaner method  which pollutes the global namespace much less  is to explicitly put the functions into an array directly like so   var dyn functions       dyn functions  populate Colours     function  arg1  arg2                        function body               dyn functions  populate Shapes     function  arg1  arg2                        function body                  calling one of the functions var result   dyn functions  populate Shapes   1  2      this works as well due to the similarity between arrays and objects var result2   dyn functions populate Shapes 1  2     This array could also be a property of some object other than the global host object too meaning that you can effectively create your own namespace as many JS libraries such as jQuery do  This is useful for reducing conflicts if when you include multiple separate utility libraries in the same page  and  other parts of your design permitting  can make it easier to reuse the code in other pages   You could also use an object like so  which you might find cleaner   var dyn functions       dyn functions populate Colours   function  arg1  arg2                        function body               dyn functions  populate Shapes     function  arg1  arg2                        function body                  calling one of the functions var result   dyn functions populate Shapes 1  2      this works as well due to the similarity between arrays and objects var result2   dyn functions  populate Shapes   1  2     Note that with either an array or an object  you can use either method of setting or accessing the functions  and can of course store other objects in there too  You can further reduce the syntax of either method for content that isn t that dynamic by using JS literal notation like so   var dyn functions                populate Colours function  arg1  arg2                        function body                          populate Shapes function  arg1  arg2                        function body                    Edit  of course for larger blocks of functionality you can expand the above to the very common  module pattern  which is a popular way to encapsulate code features in an organised manner

User · Answer

Assuming the populate Colours method is in the global namespace  you may use the following code  which exploits both that all object properties may be accessed as though the object were an associative array  and that all global objects are actually properties of the window host object   var method name    Colours   var method prefix    populate        Call function  window method prefix   method name  arg1  arg2

User · Answer

Try with this   var fn name    Colours   fn   eval  populate   fn name   fn args1 argsN

User · Answer

Within a ServiceWorker or Worker  replace window with self   self method prefix   method name  arg1  arg2     Workers have no access to the DOM  therefore window is an invalid reference  The equivalent global scope identifier for this purpose is self

User · Answer

you can do it like this   function MyClass         this abc   function             alert  abc             var myObject   new MyClass    myObject  abc

User · Answer

I would recommend NOT to use global   window   eval for this purpose  Instead  do it this way  define all methods as properties of Handler  var Handler      Handler application run   function  name    console log name     Now call it like this var somefunc    quot application run quot   Handler somefunc   jerry     Output  jerry  Case when importing functions from different files import   func1  func2   from  quot    utility quot    const Handler      func1    func2     Handler  quot func1 quot    quot sic mundus quot    Handler  quot func2 quot    quot creatus est quot

User · Answer

Hi try this    var callback function   new Function functionName    callback function      it will handle the parameters itself

[javascript] How do I call a dynamically-named method in Javascript?

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