Test your JavaScript Skills: Fundamentals-13

Introduction

Namaste, In this blog I will discuss 7 code scenarios on Javascript fundamentals.

1. Identify the output of the below program

    let sym = Symbol();
    if (sym) 
       console.log("true"); 
     else
       console.log("false");
   

   a.undefined

   b.null

   c.true

   d. false

   e.error

   Answer: c

   Reason: Symbol is a truthy value.

2. Identify the output of the below program

    if (function fx(){})
      console.log("true"); 
    else
      console.log("false");
   

   a.false

   b.error

   c.undefined

   d. true

   e.null

   Answer: d

   Reason: A function is a truthy value.

3. Identify the output of the below program

    if (Object)
      console.log("true");
    else
      console.log("false");
   

   a.false

   b.error

   c.null

   d. undefined

   e.true

   Answer: e

   Reason: The Object is pre-defined and any object is truthy.

4. Identify the output of the below program

    if ("  ") 
       console.log("true"); 
     else
       console.log("false");
   

   a.error

   b.true

   c.false

   d.undefined

   e.null

   Answer:b

   Reason: String with space is truthy.

5. Identify the output of the below program

    let fx = function(){}
   
    if (fx)
      console.log("true"); 
    else
      console.log("false");
   

   a.false

   b.error

   c.true

   d. undefined

   e.0

   Answer: c

   Reason: A function is a truthy value.

6. Identify the output of the below program

    console.log( typeof "");
   

   a. undefined

   b.null

   c.string

   d. NaN

   e.error

   Answer: c

   Reason: Empty double quotes are a string type.

7. Identify the output of the below program

     let cls = class My{};
   
    if (cls)
      console.log("true"); 
    else
      console.log("false");
   

   a.error

   b.undefined

   c.false

   d. true

   e.null

   Answer: d

   Reason: A class is a truthy value.