What is the name of a pseudo-global variable that determines whether the environment is development or production?

What happens when an error is not caught by error boundary?

How can you stop event propagation in React? (Check all that apply.)

Can you return multiple elements from a single component?

What programming concept React use for DOM manipulation and updating?

Which of following is true about componentWillReceiveProps and getDerivedStateFromProps? (Check all that apply.)

Which of the following functions is used for importing the React library?

While setting up the ReactJS environment, which of the following options must be installed?

After installing Jest CLI. the below given script object of packagejson file are edited. It should be replaced with which of the following options?

In ReactJS, which of the following key syntaxes should be used if you do not have stable IDs for rendered items?

What happens if the rendero is called again when the React element was previously rendered into container?