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.
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
You can assign the value to a variable, like this:
const letter = ('a', 'b') letter === 'b' //true
More js tutorials:
- Event bubbling and event capturing
- How to write text into to an HTML canvas
- Should you use or learn jQuery in 2020?
- The Object defineProperty() method
- The ES2017 Guide
- The String padEnd() method
- How to use Async and Await with Array.prototype.map()