JS/TS 语法：内部赋值的解构赋值

Question

I just stumbled upon this line of TS code :

const { title = item.text } = item;

It seems to be a destructuring assigment but what does the assignment within the curly brackets do?

Answer 1

The inner assignment provides a default value :

In case item.title is undefined title will be assign item.text instead.