Salesforce Salesforce Certifications JAVASCRIPT-DEVELOPER-I Questions & Answers

• Question 51:

  Given the following code: let x = null; console.log(typeof x); What is the output?

  A. "object"

  B. "undefined"

  C. "null"

  D. "x"

  Correct Answer: A

• Question 52:

  Refer to the code snippet below:

  Let array = [1, 2, 3, 4, 4, 5, 4, 4];

  For (let i =0; i

  if (array[i] === 4) {

  array.splice(i, 1);

  }

  }

  What is the value of the array after the code executes?

  A. [1, 2, 3, 4, 5, 4, 4]

  B. [1, 2, 3, 4, 4, 5, 4]

  C. [1, 2, 3, 4, 5, 4]

  D. [1, 2, 3, 5]

  Correct Answer: C

• Question 53:

  What is the result of the code block?

  A. The console logs only `flag'.

  B. The console logs `flag' and another flag.

  C. An error is thrown.

  D. The console logs `flag' and then an error is thrown.

  Correct Answer: D

• Question 54:

  Refer to the code:

  

  Given the code above, which three properties are set pet1? Choose 3 answers:

  A. Name

  B. canTalk

  C. Type

  D. Owner

  E. Size

  Correct Answer: BCE

• Question 55:

  Refer to the code below:

  Const myFunction = arr => {

  Return arr.reduce((result, current) =>{

  Return result = current;

  }, 10};

  }

  What is the output of this function when called with an empty array ?

  A. Returns 0

  B. Throws an error

  C. Returns 10

  D. Returns NaN

  Correct Answer: D

• Question 56:

  Refer to following code:

  class Vehicle {

  constructor(plate) {

  This.plate =plate;

  }

  }

  Class Truck extends Vehicle {

  constructor(plate, weight) {

  //Missing code

  This.weight = weight;

  }

  displayWeight() {

  console.log(`The truck ${this.plate} has a weight of ${this.weight}lb.');}}

  Let myTruck = new Truck(`123AB', 5000);

  myTruck.displayWeight();

  Which statement should be added to line 09 for the code to display `The truck 123AB has a weight of 5000lb.'?

  A. Super.plate =plate;

  B. super(plate);

  C. This.plate =plate;

  D. Vehicle.plate = plate;

  Correct Answer: B

• Question 57:

  A developer writes the code below to calculate the factorial of a given number

  function sum(number){

  return number * sum(number-1);

  }

  sum(3);

  what is the result of executing the code.

  A. 0

  B. 6

  C. Error

  D. -Infinity

  Correct Answer: C

• Question 58:

  A developer wants to create an object from a function in the browser using the code below.

  

  What happens due to the lack of the mm keyword on line 02?

  A. window.name is assigned to 'hello' and the variable = remains undefined.

  B. window.m Is assigned the correct object.

  C. The m variable is assigned the correct object but this.name remains undefined.

  D. The m variable is assigned the correct object.

  Correct Answer: A

• Question 59:

  Refer to the following array:

  Let arr = [ 1,2, 3, 4, 5];

  Which three options result in x evaluating as [3, 4, 5] ?

  Choose 3 answers.

  A. Let x= arr.filter (( a) => (a<2));

  B. Let x= arr.splice(2,3);

  C. Let x= arr.slice(2);

  D. Let x=arr.filter((a) => ( return a>2 ));

  E. Let x = arr.slice(2,3);

  Correct Answer: BCD

• Question 60:

  Given the code below:

  const delay = sync delay => {

  Return new Promise((resolve, reject) => {

  setTimeout (resolve, delay);});};

  const callDelay =async () =>{

  const yup =await delay(1000);

  console.log(1);

  What is logged to the console?

  A. 1 2 3

  B. 1 3 2

  C. 2 1 3

  D. 2 3 1

  Correct Answer: D