The Nullish Coalescing Operator ?? in JavaScript
Briefly

The nullish coalescing operator provides a concise syntax for setting a default value if the given value is .and are the only nullish values in JavaScript.Nullish coalescing is typically used for assigning default values.Older JavaScript code often used || for assigning default values, but || is error prone because it captures all falsy values, like 0, empty string, and false.
Read at Mastering JS
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