Node.js Http2ServerResponse.hasHeader() Method

Node.js has introduced the Http2ServerResponse.hasHeader() method, an API for checking whether a specific header is currently set in outgoing HTTP/2 server responses. The method returns a boolean value: true if the header exists, false if it does not. The method takes a single parameter, the header name, and is called on an Http2ServerResponse object. Official examples demonstrate its use with the setHeader() method, showing that it correctly identifies present headers like 'Content-Type' and absent ones, with output confirming the boolean result in each case. This utility helps developers avoid duplicate headers, verify optional header presence before modification, and implement conditional response logic. It is part of the http2 module's built-in functionality, requiring no additional installation beyond Node.js's standard library.