Headers.append()

The append() method of the Headers interface appends a new value onto an existing header inside a Headers object, or adds the header if it does not already exist.

The difference between Headers.prototype.set() and append() is that if the specified header already exists and accepts multiple values, set() will overwrite the existing value with the new one, whereas append() will append the new value onto the end of the set of values.

Syntax

append(name, value)

Parameters

• name
  • : The name of the HTTP header you want to add to the Headers object.
• value
  • : The value of the HTTP header you want to add.

Return value

None (undefined).