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API > @angular/common > @angular/common/http

HttpHeaders

HttpHeaders class represents the header configuration options for an HTTP request. Instances should be assumed immutable with lazy parsing.

      
      class HttpHeaders {
  constructor(headers?: string | { [name: string]: string | string[]; })
  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.
constructor(headers?: string | { [name: string]: string | string[]; })
      
      constructor(headers?: string | { [name: string]: string | string[]; })
Parameters
headers string | { [name: string]: string | string[]; }

Optional. Default is undefined.

Methods

has()

Checks for existence of a header by a given name.
has(name: string): boolean
      
      has(name: string): boolean
Parameters
name string

The header name to check for existence.
Returns

boolean: Whether the header exits.

get()

Returns the first header value that matches a given name.
get(name: string): string | null
      
      get(name: string): string | null
Parameters
name string

The header name to retrieve.
Returns

string | null: A string if the header exists, null otherwise

keys()

Returns the names of the headers.
keys(): string[]
      
      keys(): string[]
Parameters

There are no parameters.

Returns

string[]: A list of header names.

getAll()

Returns a list of header values for a given header name.
getAll(name: string): string[] | null
      
      getAll(name: string): string[] | null
Parameters
name string

The header name from which to retrieve the values.
Returns

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

append()

Appends a new header value to the existing set of header values.
append(name: string, value: string | string[]): HttpHeaders
      
      append(name: string, value: string | string[]): HttpHeaders
Parameters
name string

The header name for which to append the values.
value string | string[]
Returns

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

set()

Sets a header value for a given name. If the header name already exists, its value is replaced with the given value.
set(name: string, value: string | string[]): HttpHeaders
      
      set(name: string, value: string | string[]): HttpHeaders
Parameters
name string

The header name.
value string | string[]

Provides the value to set or overide for a given name.
Returns

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

delete()

Deletes all header values for a given name.
delete(name: string, value?: string | string[]): HttpHeaders
      
      delete(name: string, value?: string | string[]): HttpHeaders
Parameters
name string

The header name.
value string | string[]

The header values to delete for a given name.

Optional. Default is undefined.
Returns

HttpHeaders: A clone of the HTTP header object.