Javascript, string interpolated function name

Question

I'm a javascript newbie.

I have a line of code:

data.content_teaser.image_square_attachment_url

square can change: I have a variable called contentType that can be 'square', or 'vertical' or 'horizontal'.

In ruby I can use send with the string interpolation, how can I obtain the same in js?

Something like "data.content_teaser.image_" + contentType + "_attachment_url"

I cannot understand how can I change using the string of a var a method name... — Roberto Pezzali, Jun 02 '17 at 11:53
I have a variable that is a string. I need to use the string value to change the function name... — Roberto Pezzali, Jun 02 '17 at 11:55

score 1 · Accepted Answer · answered Jun 02 '17 at 12:05

Javascript has 2 ways to access object properties/methods - dot-notation and square-bracket-notation. The latter uses a string what you could build up in the normal way you would for any string. So these 2 are equivalent:

data.content_teaser.image_square_attachment_url;
data.content_teaser["image_square_attachment_url"];

So, to answer your question:

var contentType = "square";
var result = data.content_teaser["image_" + contentType + "_attachment_url"];

geo · Answer 2 · 2017-06-02T12:27:39.703

0

You can use Javascript's string interpolation since ES2015 look here https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Template_literals :

`string text ${expression} string text`

So, you can use something like this :

let s = `image_${contentType}_attachment_url`

And after that :

data.content_teaser[s]

edited Jun 02 '17 at 12:27

answered Jun 02 '17 at 12:01

geo

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Javascript, string interpolated function name

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