Test your JavaScript Skills : Boolean() function

Introduction

Namaste, In this blog I will discuss 10 code scenarios on the Boolean() function.

1. Identify the output of the below program

    let v = Boolean(undefined);
    console.log(v);
   

   a.true

   b.false

   c.undefined

   d.null

   e.error

   Answer: b

   Reason: The boolean() function for undefined returns false

2. Identify the output of the below program

    let v = Boolean(10);
    console.log(v);
   

   a.true

   b.false

   c.null

   d.undefined

   e.error

   Answer: a

   Reason: The boolean() function for 10 returns true

3. Identify the output of the below program

    let v = Boolean(null);
    console.log(v);
   

   a.false

   b.true

   c.null

   d.undefined

   e.error

   Answer: a

   Reason: The boolean() function for null returns false

4. Identify the output of the below program

    let v = Boolean([]);
    console.log(v);
   

   a.[]

   b.{}

   c.true

   d.false

   e.error

   Answer:c

   Reason: The boolean() function for [](empty array) returns true

5. Identify the output of the below program

    let v = Boolean(NaN);
    console.log(v);
   

   a.NaN

   b.error

   c.false

   d.true

   e.error

   Answer: c

   Reason: The boolean() function for NaN returns false

6. Identify the output of the below program

    let v = Boolean(0);
    console.log(v);
   

   a.0

   b.false

   c.true

   d.error

   e.undefined

   Answer: b

   Reason: The boolean() function for 0 returns false

7. Identify the output of the below program

    let v = Boolean("");
    console.log(v);
   

   a.error

   b.undefined

   c.null

   d.true

   e.false

   Answer: e

   Reason: The boolean() function for an empty string is false

8. Identify the output of the below program

    let v = Boolean("JS");
    console.log(v);
   

   a.error

   b.undefined

   c.JS

   d.true

   e.false

   Answer: d

   Reason: The boolean() function for a string is true

9. Identify the output of the below program

    let v = Boolean({});
    console.log(v);
   

   a.error

   b.undefined

   c.null

   d.true

   e.false

   Answer: d

   Reason: The boolean() function for an object string is true

10. Identify the output of the below program

    let v = Boolean(-0);
    console.log(v);
    

    a.error

    b.undefined

    c.null

    d.true

    e.false

    Answer: e

    Reason: The boolean() function for -0 is false