Salesforce Salesforce Certifications JAVASCRIPT-DEVELOPER-I Questions & Answers

• Question 121:

  Refer to code below:

  Let a ='a';

  Let b;

  // b = a;

  console.log(b);

  What is displayed when the code executes?

  A. ReferenceError: b is not defined

  B. A

  C. Undefined

  D. Null

  Correct Answer: C

• Question 122:

  Given the code below:

  01 function GameConsole (name) {

  02 this.name = name;

  03 }

  05 GameConsole.prototype.load = function(gamename) {

  06 console.log( ` $(this.name) is loading agame : $(gamename) ...`);

  07 )

  08 function Console 16 Bit (name) {

  09 GameConsole.call(this, name) ;

  10 }

  11 Console16bit.prototype = Object.create ( GameConsole.prototype) ;

  12 //insert code here

  13 console.log( ` $(this.name) is loading a cartridge game :$(gamename) ...`);

  14 }

  15 const console16bit = new Console16bit(` SNEGeneziz ');

  16 console16bit.load(` Super Nonic 3x Force ');

  What should a developer insert at line 15 to output the following message using the method ?

  > SNEGeneziz is loading a cartridgegame: Super Monic 3x Force . . .

  A. Console16bit.prototype.load(gamename) = function() {

  B. Console16bit.prototype.load = function(gamename) {

  C. Console16bit = Object.create(GameConsole.prototype).load = function (gamename) {

  D. Console16bit.prototype.load(gamename) {

  Correct Answer: B

• Question 123:

  Refer to the code below:

  01 const server = require(`server');

  02 /* Insert code here */

  A developer imports a library that creates a web server.The imported library uses events and callbacks to start the servers

  Which code should be inserted at the line 03 to set up an event and start the web server ?

  A. Server.start ();

  B. server.on(` connect ' , ( port) => { console.log(`Listening on ' , port);})

  C. server()

  D. serve(( port) => (

  E. console.log( `Listening on ', port) ;

  Correct Answer: B

• Question 124:

  A developer has the following array of student test grades:

  Let arr = [ 7, 8, 5, 8, 9 ];

  The Teacher wants to double each score and then see an array of the students who scored more than 15 points.

  How should thedeveloper implement the request?

  A. Let arr1 = arr.filter(( val) => ( return val > 15 )) .map (( num) => ( return num *2 ))

  B. Let arr1 = arr.mapBy (( num) => ( return num *2 )) .filterBy (( val ) => return val > 15 )) ;

  C. Let arr1 = arr.map((num) => num*2). Filter (( val) => val > 15);

  D. Let arr1 = arr.map((num) => ( num *2)).filterBy((val) => ( val >15 ));

  Correct Answer: C

• Question 125:

  Refer to the code below:

  Let str = `javascript';

  Str[0] = `J';

  Str[4] = 'S';

  After changing the stringindex values, the value of str is `javascript'. What is the reason

  for this value:

  A. Non-primitive values are mutable.

  B. Non-primitive values are immutable.

  C. Primitive values are mutable.

  D. Primitive values are immutable.

  Correct Answer: D

• Question 126:

  Given the code below:

  Which three code segments result in a correct conversion from number to string? Choose 3 answers

  A. let strValue = numValue. toString();

  B. let strValue = * * 4 numValue;

  C. let strValue = numValue.toText ();

  D. let scrValue = String(numValue);

  E. let strValue = (String)numValue;

  Correct Answer: ABD

• Question 127:

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

  Function factorial(number) {

  Return number + factorial(number -1);

  }

  factorial(3);

  What isthe result of executing line 04?

  A. 0

  B. 6

  C. -Infinity

  D. RuntimeError

  Correct Answer: D

• Question 128:

  Refer to the following code:

  Let sampleText = `The quick brown fox jumps';

  A developer needs to determine if a certainsubstring is part of a string.

  Which three expressions return true for the given substring ?

  Choose 3 answers

  A. sampleText.includes(`fox');

  B. sampleText.includes(` quick ', 4);

  C. sampleText.includes(` Fox ', 3)

  D. sampleText.includes(` fox ');

  E. sampleText.includes(` quick ') !== -1;

  Correct Answer: BDE

• Question 129:

  Refer to thecode below:

  let sayHello = () => {

  console.log (`Hello, world!');

  };

  Which code executes sayHello once, two minutes from now?

  A. setTimeout(sayHello, 12000);

  B. setInterval(sayHello, 12000);

  C. setTimeout(sayHello(), 12000);

  D. delay(sayHello, 12000);

  Correct Answer: A

• Question 130:

  A developer wants to leverage a module to print a price in pretty format, and has imported a method as shown below:

  Import printPrice from `/path/PricePrettyPrint.js';

  Based on the code, what mustbe true about the printPrice function of the PricePrettyPrint module for this import to work ?

  A. printPrice must be be a named export

  B. printPrice must be an all export

  C. printPrice must be the default export

  D. printPrice must be a multi exportc

  Correct Answer: C