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This is the archived documentation for Angular v17. Please visit angular.dev to see this page for the current version of Angular.

HttpHeaders

Represents the header configuration options for an HTTP request. Instances are immutable. Modifying methods return a cloned instance with the change. The original object is never changed.

      
      class HttpHeaders {
  constructor(headers?: string | { [name: string]: string | number | (string | number)[]; } | Headers)
has(name: string): boolean
get(name: string): string | null
keys(): string[]
getAll(name: string): string[] | null
append(name: string, value: string | string[]): HttpHeaders
set(name: string, value: string | string[]): HttpHeaders
delete(name: string, value?: string | string[]): HttpHeaders }

Constructor

Constructs a new HTTP header object with the given values.

This class is "final" and should not be extended. See the public API notes.

      
      constructor(headers?: string | { [name: string]: string | number | (string | number)[]; } | Headers)
    
Parameters
headers string | { [name: string]: string | number | (string | number)[]; } | Headers

Optional. Default is undefined.

Methods

Checks for existence of a given header.

      
      has(name: string): boolean
    
Parameters
name string

The header name to check for existence.

Returns

boolean: True if the header exists, false otherwise.

Retrieves the first value of a given header.

      
      get(name: string): string | null
    
Parameters
name string

The header name.

Returns

string | null: The value string if the header exists, null otherwise

Retrieves the names of the headers.

      
      keys(): string[]
    
Parameters

There are no parameters.

Returns

string[]: A list of header names.

Retrieves a list of values for a given header.

      
      getAll(name: string): string[] | null
    
Parameters
name string

The header name from which to retrieve values.

Returns

string[] | null: A string of values if the header exists, null otherwise.

Appends a new value to the existing set of values for a header and returns them in a clone of the original instance.

      
      append(name: string, value: string | string[]): HttpHeaders
    
Parameters
name string

The header name for which to append the values.

value string | string[]

The value to append.

Returns

HttpHeaders: A clone of the HTTP headers object with the value appended to the given header.

Sets or modifies a value for a given header in a clone of the original instance. If the header already exists, its value is replaced with the given value in the returned object.

      
      set(name: string, value: string | string[]): HttpHeaders
    
Parameters
name string

The header name.

value string | string[]

The value or values to set or override for the given header.

Returns

HttpHeaders: A clone of the HTTP headers object with the newly set header value.

Deletes values for a given header in a clone of the original instance.

      
      delete(name: string, value?: string | string[]): HttpHeaders
    
Parameters
name string

The header name.

value string | string[]

The value or values to delete for the given header.

Optional. Default is undefined.

Returns

HttpHeaders: A clone of the HTTP headers object with the given value deleted.