The ?? (nullish coalescing) and || (logical OR) operators in JavaScript are used to provide a default value when the expression on the left-hand side is not provided. They are helpful when handling cases where a value might not exist or is falsy, and you want to ensure a fallback is provided.
What Does The ?? Operator Means: The ?? operator is used to provide a default value when the expression on the left-hand side is either null or undefined, but allows other falsy values like 0, false, or '' (empty string) to remain. This simple means that even if the value of the left-hand side is 0, false, of '' , the result will return the left hand side.
let value = 0; const testValue = value ?? 'Default Value' output : 0
What Does The || Operator Means: The || is quite similar to the ?? operator, but what distinguish the ?? from the || is that it checks for all falsy values.const count = 0; const testCount = count || 10; output: 10 (because 0 is falsy).
Tip: Use ?? when working with APIs, optional parameters, or dynamic data that may not always be defined. You can provide a fallback without affecting valid falsy values like false or an empty string.