I recently discovered a curious yet possibly useful thing in JavaScript, related to the comma operator.
I mostly use commas to separate properties in an object, or array items.
However I never gave much attention the usage of it inside an expression.
Take this:
('a', 'b')
Both expressions (in this case strings) are evaluated, and this returns the last element, the expression after the last comma. In this example it returns 'b'
.
You can assign the value to a variable, like this:
const letter = ('a', 'b')
letter === 'b' //true