What is double question mark react?

Conclusion. The JavaScript double question mark is also known as the nullish coalescing operator. It’s an operator that simply returns the right-side expression when the left side expression is either null or undefined .

If double question marks are uses it is to emphasise something in return, usually from the shock of the previous thing said . For example, if I said: ‘My dog just died’ (sad, but used for example…) Someone may reply.

operator known as Null Coalescing Operator . It returns its first operand if it exists and is not NULL; otherwise, it returns its second operand. It evaluates from left to right.