REACT NATIVE QUIZ DESCRIPTION

What is the default port where webpack-server runs? 
 

  • 3000

  • 8080

  • 3030

  • 6060

What is the default port for webpack dev server? 

  • 3000 
     

  •  8080 
     

  • 3306 
     

  •  8808 

Which of the following acts as the input of a class-based component? 

  • Class 
     


  • Factory 
     

  •  
    Render 

     


  • Props 
     

A class is a type of function, but instead of using the keyword function to 
initiate it, which keyword do we use? 
 

  • Constructor 

     


  • Class 
     


  • Object 
     


  • DataObject 
     

Which of the following is a correct definition of state in react? 

  • A persistent storage 
     

  • An internal data store (object) of component 
     

  •  Both 
     

  • None 

Virtual DOM creates a copy of the whole DOM object 
 

  •  FALSE 
     


  •  TRUE 
     

In ES6 – Which method refers to the parent class? 
 

  • parent() 
     


  • super() 
     


  • top() 
     


  • main() 

What is the declarative way to render a dynamic list of components based 
on values in an array? 
 

  • Using the reduce array method 
     

  •  
    Using the <Each /> component 
     


  • Using the Array.map() method 
     


  • With a for/while loop 

Which of the following method is not a part of ReactDOM? 

  • ReactDOM.destroy() 
     


  • ReactDOM.hydrate() 
     


  • ReactDOM.createPortal() 
     


  • ReactDOM.findDOMNode() 

What is a good use case for using a function while rendering a dynamic list 
of items 
 

  • If we need to compute a value based on properties of items in the loop.

  • None. Functions should not be used while rendering a dynamic list. 

  • To make the code shorter 
     

  • None of the above

Which ReactJS function renders HTML to the web page? 
 

  • render() 
     


  • ReactDOM.render() 
     


  • renders() 
     


  • ReactDOM.renders() 
     

Which of the following is the correct name of React.js?

  • React 
     


  • React.js 
     


  • ReactJS 
     


  • All of the above 

What will happen if you render an input element with disabled = {false}? 

  • It will be rendered as disabled 
     


  • It will not be rendered at all 
     


  • It will be rendered as enabled 
    . 


  • You cannot set it false. 

Which of the following statement is true for controlled components in 
React.js? 
 

  • The source of truth is DOM. 
     


  • The source of truth can be anything. 
     


  • The source of truth is a component state. 
     


  • None of the above. 

The state in react can be updated by call to setState method. These calls 
are 

  • Synchronous in nature 
     

  •  Asynchronous in nature 
     

  • Are asynchronous but can be made synchronous when required 
     

  • None of above 
     

Select the correct statement about uncontrolled components. 
 

  •  It maintains its internal states 
     


  •  data is controlled by the DOM itself 
     


  •  A ref is used for their current values 
     


  •  All 

What are Props? 

  • Props are arguments passed into React components 
     


  • Props are functions in the ReactJS 
     


  • Props are used to returns multiple values from the function 

     


  • All of the above 
     

Why is the usage of setState? 
 


  • Invoke code after the setState operation is done. 

     



  • Replace the state completely instead of the default merge action. 
     


  • Access the previous state before the setState operation. 
     



  • None of the above. 
     

Select apps which used react native . 
 

  •  All 
     


  •  Instagram 
     


  •  pinterest 
     


  •  Airbnb 

In ES6 – A class is a type of ____. 
 

  • Basic datatype 
     

  • Derived datatype 
     


  • Variable 
     


  • Function 
     

What is React Js? 

  • Javascript framework 
     

  • Javascript library 
     

  •  Javascript file 
     

  • None of the Above 

What are two ways data gets handled in react? 
 

  • state & props 
     

  •  services & components 
     


  • state & services 
     

  • state & component 

Which ReactJS command is used to set up everything you need to run a 
React Application? 
 

  • create-react-app 
     


  • new-react-app 
     


  • create-new-reactapp 
     


  • react-app 

In ES6 – What is the correct syntax of class inheritance? 

  • class class1 extends class2{...} 
     


  • class class1 extends | class2{...} 

     


  • class class1 | extends class2{...} 

     


  • class class1 | extends | class2{...} 
     

In relation to React js component lifecycle, which statement is true 

  • only function component can have life cycle 

  • Only class components can have life cycle 

  • Both type of components can have life cycle 

  • None of above 

Which ReactJS command is used to create a new application? 
 

  • create-react-app 
     


  • new-react-app 
     


  • create-new-reactapp 
     


  • react-app 

What does ES6 stand for? 
 

  • ECMAScript 6 
     


  • ECMA 6 
     


  • ECMAJavaScript 6 
     


  • EJavaScript 6 

Which of the following best defines the "key" prop? 

  • "Key" prop is used to look pretty, and there is no benefit whatsoever. 
     


  • "Key" prop is a way for React to identify a newly added item in a list and 
    compare it during the "diffing" algorithm. 
     


  • It is one of the attributes in HTML. 
     


  • It is NOT commonly used in an array. 

 JSX stands for 

  •  JavaScript XML 
     


  •  JavaScreenXML 
     


  •  JointScript XML 
     


  •  none 

Which of the following command is used to install create-react-app? 
Play Videox 

  • npm install -g create-react-app 
     


  • npm install create-react-app 
     


  • npm install -f create-react-app 
     


  • install -g create-react-app