Table of Contents

    ReactJS - Keys and Ref

    MCQ Section

    MCQ 1
    Ref is used to refer an/a element/component returned by _______________.
    MCQ 2
    If our elements are dynamic, React can keep track of the changes using keys.
    MCQ 3
    We can go for ________ when there is a possibility that our user could change the data.
    MCQ 4
    An altered component may be uniquely identified with the help of ref.
    MCQ 5
    Keys used within arrays should be globally unique.
    MCQ 6
    To Prevent firing of the component's lifecycle methods you can use null from render method.
    MCQ 7
    Which lifecycle event is invoked before rendering and when new props or state is being received?
    MCQ 8
    Batching of multiple setState() calls in a single update is possible.
    MCQ 9
    If you create an element, you cannot change its ________.