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What does "optional parameter" mean in programming?
optional parameter is one of the most common terms in software development. This guide explains what it means, how it is used in practice, and why it matters, with real examples from the developer world.
Definition
A function parameter that does not need to be provided by the caller. In TypeScript it is marked with a ? after the name. The function must handle the case where the value is undefined.
Example
"function log(message: string, level?: string) {} // level is optional"
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