Headers

TThe Headers() constructor creates a new Headers object.

new Headers();
new Headers(init);

Parameters

• init (optional)

  An object containing any HTTP headers you want to prepopulate your Headers object with. This can be a simple object literal with String values, an array of name-value pairs, where each pair is a 2-element string array; or an existing Headers object. In the last case, the new Headers object copies its data from the existing Headers object.

INFO

Request and Response Headers are immutable. This means, if you need to modify Request headers for downstream fetch requests, or modify Response headers prior to returning a Response. You will need to create a new Headers() object.