Call JavaScript Function by String Name

C
Published in: Javascript

You can use eval() method to invoke a JavaScript function whose name is stored in a string variable but there’s a better method that doesn’t require eval.

Let’s say we have a function helloWorld(e) that takes variable and prints it.

function helloWorld(e) {
  e = e || "Anonymous";
  console.log("Hello " + e);
  return;
}

We declare a variable that has the function name and another variable that stores the arguments.

// Function name to invoke
var fnName = "helloWorld";

// Params to pass to the function
var params = "ctrlq.org";

// Call function using Window object
window[fnName](params);

This can be useful for invoking Google Apps Script functions as well. However, since it is server-side code and not a web browser environment, we use this to refer to the object that contains it.

this[fnName](params);
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Published in: Javascript

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Web Geek, Google Developer Expert
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Amit Agarwal

Amit Agarwal is a Google Developer Expert in Google Workspace and Google Apps Script. He holds an engineering degree in Computer Science (I.I.T.) and is the first professional blogger in India. He is the developer of Mail Merge for Gmail and Document Studio. Read more on Lifehacker and YourStory

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