Using .includes() on a string never works

[ague]

Whenever I attempt to use the '.includes()' method on string in ThingWorx composer, I always get an error saying that the .includes method can not be found on the object. I even log the type of the variable that I am trying to edit, just to make sure it is in fact a string. And I still can not get around this.

Here's an example of what I'm talking about:

var myString = 'I am trying to debug some crazy ThingWorx issues';

var myBoolean = myString.includes('ThingWorx');

*the above code will throw the error:

'TypeError: Cannot find function includes in object I am trying to debug some crazy ThingWorx issues. (GetProcessPartID#22)]'

But if I log 'typeof myString', it will log 'string'.

What gives?!

[Rick-Stanley · Accepted solution]

The .includes() function is not available.

Use .indexOf() instead:

(myString.indexOf('ThingWorx') != -1)

[ague]

Is there a rhyme or reason to why some javascript methods are available and others not? 

[Rick-Stanley]

Yes, ThingWorx uses a custom version of Rhino for JavaScript processing in Services that conforms (with some exceptions) to the ECMAScript 5 specification.The ECMAScript 5 Specification can be found here.

[ague]

Thank you! This is very helpful!