Question

110

How to declare a custom class in google scripts?

rated 0 times [ 112] [ 2] / answers: 1 / hits: 39128 / 9 Years ago, fri, october 16, 2015, 12:00:00

I want to create a class inside my script.

Google Apps Script language is based on javaScript, so I took an example from a javaScript manual:

class Polygon {

  constructor(height, width) {

    this.height = height;

    this.width = width;

  }

}

However, this doesn't work. I get this error message:

Missing ; before statement. (line 1, file Code)

Does that mean it's not possible to create new classes in google scripts?

Or is there a different syntax I'm supposed to use?

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grayson

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4 Years ago

answered 9 Years ago ravenl · Accepted Answer

Update:

As of spring 2020 Google has introduced a new runtime for Apps Script which supports Classes.

New scripts use this runtime by default, while older scripts must be converted. A prompt is displayed in the script editor, from which you can convert your scripts.

// V8 runtime

class Rectangle {

  constructor(width, height) { // class constructor

    this.width = width;

    this.height = height;

  }



  logToConsole() { // class method

    console.log(`Rectangle(width=${this.width}, height=${this.height})`);

  }

}



const r = new Rectangle(10, 20);

r.logToConsole();  // Outputs Rectangle(width=10, height=20)

Original (old) answer:

Historically Javascript is a "classless" language, classes are a newer feature which haven't been widely adopted yet, and apparently are not yet supported by Apps Script.

Here's an example of how you can imitate class behaviour in Apps Script:

var Polygon = function(height, width){

  this.height = height;

  this.width = width;

  

  this.logDimension = function(){

    Logger.log(this.height);

    Logger.log(this.width);

  }

};



function testPoly(){

  var poly1 = new Polygon(1,2);

  var poly2 = new Polygon(3,4);

  

  Logger.log(poly1);

  Logger.log(poly2);

  poly2.logDimension();

}