Top-Level API

Question 1

React.Component

Answer 1

The base class for React Components defined with ES6 classes.

Question 2

React.createClass()

Answer 2

Create a component class

params: specification
returns: ReactClass

specification
an object that defines (at least) a render method

Question 3

React.createElement()

Answer 3

Creates a ReactElement… either an html tag or a ReactClass. This is equivalent to JSX

params: type[, props[, children …]]
returns: ReactElement

- type
    Either a string for tag name, or an object for ReactClass
- props
    object with the props to pass in
- children
    child elements

Question 4

React.cloneElement()

Answer 4

Clones the element with shallow merge for props. Key and ref from original element are preserved.

params: element[, props[, children …]]
returns: ReactElement

- element
    element to clone
- props
    object with the props to pass in
- children
    child elements

Question 5

React.createFactory()

Answer 5

Return a function that produces ReactElements of a given type

params: type
returns: factoryFunction

• type
  HTML string or ReactClass

Question 6

React.isValidElement()

Answer 6

Verify that object is ReactElement

params: element
returns: boolean

Question 7

React.DOM

Answer 7

Convenience wrappers around React.createElement for DOM components

Question 8

React.PropTypes

Answer 8

A list of types that can be used to validate the props being passed in

Question 9

React.Children

Answer 9

convenience functions for dealing with the this.props.children opaque data structure

Question 10

React.children.map()

Answer 10

Returns an array of the children with fn applied

params: children, fn[, thisArg]
returns: array | null | undefined

Note: if children is a nested object, it will be traversed. fn will not be passed the container

Question 11

React.Children.forEach()

Answer 11

Runs the function against all children

params: children, fn[, thisArg]

Question 12

React.Children.count()

Answer 12

Counts the children (based oh how many times map fn would be called)

params: children
returns: number

Question 13

React.Children.only()

Answer 13

Return the only child in children. Throw otherwise

params: children

Question 14

React.Children.toArray()

Answer 14

Return the children data structure as an array. Use to manipulate collections in render methods (e.g reorder or slice)

Question 15

ReactDOM

Answer 15

DOM-specific methods that can be used at the top level of an app (to go outside the React model if needed)