switch statement vs object lookup

switch-or-object-map.js

// Q: Which would you prefer to get a mapped value?

// with a `switch` statement
export function getHeaderValue(headerName: string): string {
  switch (headerName) {
    case "content-type":
      return headers.contentType();
    case "content-length":
      return headers.contentLength();
    case "content-md5":
      return headers.contentMd5Hash();
    case "etag":
      return headers.etag();
    case "last-modified":
      return headers.lastModified();
    case "accept-ranges":
      return headers.acceptRanges();
    case "cache-control":
      return headers.cacheControl();
    case "content-disposition":
      return headers.contentDisposition();
    default:
      return headerName;
  }
}

// with an object lookup
export function getHeaderValue(headerName: string): string {
  return {
    "content-type": headers.contentType(),
    "content-length": headers.contentLength(),
    "content-md5": headers.contentMd5Hash(),
    "etag": headers.etag(),
    "last-modified": headers.lastModified(),
    "accept-ranges": headers.acceptRanges(),
    "cache-control": headers.cacheControl(),
    "content-disposition": headers.contentDisposition()
  }[headerName] || headerName;
}