Define dynamic function in javascript

Question

I am having SetUpTest() method, function name will be generated on-load of script by fetching window object. testShieldVal.js_name is variable,

testShieldVal = window.testObject || {};

SetUpTest = testShieldVal.js_name+"SetUp";

function SetUpTest() {
  new atoShieldVal.js_name.OnloadCallback(grecaptcha);
}

How can I define this function with dynamic name efficiently?

This seems like an XY problem; the easier solution is to put functions in an object w/ a key. — Dave Newton, Jun 08 '21 at 17:44
What is `atoShieldVal`? What is the data type of `.js_name`? — trincot, Jun 08 '21 at 17:50
@trincot function body can be ignored, I just need function name to be taken dynamically as it changes with change window object. **`testShieldVal.js_name = "login";`** Let say, `function SetUpTest() { return "testing"; }` — Aakanksha Dahima, Jun 09 '21 at 13:02
Why not define that function on `testShieldVal`? Like `testShieldVal.setup = function () { return "testing"; };` Dynamic function names are always a bad idea. — trincot, Jun 09 '21 at 13:05

score 0 · Answer 1 · answered Jun 08 '21 at 19:15

If I understand your question correctly, you are looking to define a function with a dynamic name.

In that case you should add the method to the window object using window[functionName] = function() { ... }

This results in:

testShieldVal = window.testObject || {};

SetUpTest = testShieldVal.js_name+"SetUp";

window[SetUpTest] = function {
  new atoShieldVal.js_name.OnloadCallback(grecaptcha);
}

When window.testObject.js_name is 'Demo' then Your function can then be called via DemoSetUp(). This will automatically look in the window object for a method with that name.

Define dynamic function in javascript

1 Answers1