---
name: "up.Params"
area: "API"
kind: "class"
parent: "up.form module"
url: "https://unpoly.com/api/up.Params"
---
# `up.Params`
The `up.Params` class offers a consistent API to read and manipulate request parameters independent of their type.
Request parameters are used in [form submissions](https://unpoly.com/api/up.Params.fromForm.md) and [URLs](https://unpoly.com/api/up.Params.fromURL.md). Methods like [`up.submit()`](https://unpoly.com/api/up.submit.md) or [`up.render()`](https://unpoly.com/api/up.render.md) accept request parameters as a `{ params }` option.
## Supported parameter types {#supported-parameter-types}
The following types of parameter representation are supported:
1. An object like `{ email: 'foo@bar.com' }`
2. A query string like `'email=foo%40bar.com'`
3. An array of `{ name, value }` objects like `[{ name: 'email', value: 'foo@bar.com' }]`
4. A [FormData](https://developer.mozilla.org/en-US/docs/Web/API/FormData) object.
---
## Features {#features}
- ### [new up.Params([params])](https://unpoly.com/api/up.Params.new.md) (Class constructor)
Constructs a new `up.Params` instance.
- ### [up.Params.prototype.add(name, value)](https://unpoly.com/api/up.Params.prototype.add.md) (Instance method)
Adds a new entry with the given `name` and `value`.
- ### [up.Params.prototype.addAll(params)](https://unpoly.com/api/up.Params.prototype.addAll.md) (Instance method)
Adds all entries from the given list of params.
- ### [up.Params.prototype.addField(field, [options])](https://unpoly.com/api/up.Params.prototype.addField.md) (Instance method) (experimental)
Adds params from the given HTML form field.
- ### [up.Params.prototype.clear()](https://unpoly.com/api/up.Params.prototype.clear.md) (Instance method)
Removes all params from this object.
- ### [up.Params.prototype.delete(name)](https://unpoly.com/api/up.Params.prototype.delete.md) (Instance method)
Deletes all entries with the given `name`.
- ### [up.Params.prototype.get(name)](https://unpoly.com/api/up.Params.prototype.get.md) (Instance method)
Returns the first param value with the given `name`.
- ### [up.Params.prototype.getAll(name)](https://unpoly.com/api/up.Params.prototype.getAll.md) (Instance method) (experimental)
Returns an array of all param values with the given `name`.
- ### [up.Params.prototype.getFirst(name)](https://unpoly.com/api/up.Params.prototype.getFirst.md) (Instance method) (experimental)
Returns the first param value with the given `name`.
- ### [up.Params.prototype.set(name, value)](https://unpoly.com/api/up.Params.prototype.set.md) (Instance method)
Sets the `value` for the entry with given `name`.
- ### [up.Params.prototype.toArray()](https://unpoly.com/api/up.Params.prototype.toArray.md) (Instance method) (experimental)
Returns an array representation of this `up.Params` instance.
- ### [up.Params.prototype.toFormData()](https://unpoly.com/api/up.Params.prototype.toFormData.md) (Instance method)
Returns a `FormData` representation of this `up.Params` instance.
- ### [up.Params.prototype.toObject()](https://unpoly.com/api/up.Params.prototype.toObject.md) (Instance method) (experimental)
Returns an object representation of this `up.Params` instance.
- ### [up.Params.prototype.toQuery()](https://unpoly.com/api/up.Params.prototype.toQuery.md) (Instance method)
Returns a query string for this `up.Params` instance.
- ### [up.Params.prototype.toURL(base)](https://unpoly.com/api/up.Params.prototype.toURL.md) (Instance method) (experimental)
Builds a URL string from the given base URL and this `up.Params` instance as a query string.
- ### [up.Params.fromContainer(container, [options])](https://unpoly.com/api/up.Params.fromContainer.md) (Class method) (experimental)
Constructs a new `up.Params` instance from the fields within the given container.
- ### [up.Params.fromFields(fields)](https://unpoly.com/api/up.Params.fromFields.md) (Class method) (experimental)
Constructs a new `up.Params` instance from one or more HTML form fields.
- ### [up.Params.fromForm(form, [options])](https://unpoly.com/api/up.Params.fromForm.md) (Class method)
Constructs a new `up.Params` instance from the given `