Is a function return value possible as an array key?

Question

I made a lazy utility function that I wanted to pass as my arrays key but I was getting syntax errors, is it possible to pass a function inside the array as it's key?

function encloseAttrSelector(attr, value)
{
    return '[' + attr + '="' + value + '"]';
}   

..

example (typically more than one pair):

var data = { encloseAttrSelector('name', 'username'):  row.first().text() };

Answer 1

In ES6 ES2015 (the newest official standard for the language) yes, but in most real-life contexts no. You can however do this:

var data = {};
data[encloseAttrSelector('name', 'username')] = row.first().text();

The new ES2015 syntax is:

var data = { [encloseAttrSelector('name', 'username')] : row.first().text() };

That is, square brackets around what would normally be just the property name in an object initializer expression. Inside the square brackets can be any expression.

Answer 2

For more than one pair, please do this:

var data = {};
data[encloseAttrSelector('name', 'username')] = row.first().text();