Accept a variable number of arguments.
Section: Functions and Parameters
Use rest parameters
typescript
typescript
function joinWith(separator: string, ...parts: string[]) {
return parts.join(separator);
}Explanation
Rest parameters are typed as arrays.
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Same sheet · prioritizing Functions and Parameters
Use default parameters
Provide a default value and keep a concrete type.
Declare function overloads
Expose multiple call signatures with one implementation.