Nullish Coalescing Operator
The nullish coalescing operator (
??) is also new to ES2020. It works much like logical OR (
||) except that it will short circuit (or return) for non-null, non-undefined falsy values such as false, 0, and empty strings whereas OR would not. This is useful for setting defaults that may include these kinds of values.
let initialValue = 0; let x = initialValue || 1; let y = initialValue ?? 1; console.log(x); // 1 console.log(y); // 0