Salesforce JAVASCRIPT-DEVELOPER-I Online Practice Questions and Exam Preparation

Salesforce JAVASCRIPT-DEVELOPER-I Online Questions & Answers

• Question 1:

  Refer to the following code:

  

  Which two statement could be inserted at line 17 to enable the function call on line 18? Choose 2 answers

  A. Object.assign (leo, tony);
  B. Object.assign (leo. Tiger);
  C. leo.roar = () => { console.log('They\'re pretty good!'););
  D. leo.prototype.roar = ( ) =>( console.log('They\'re pretty good!'); };
  A. Object.assign (leo, tony);
  C. leo.roar = () => { console.log('They\'re pretty good!'););

• Question 2:

  Given the JavaScript below:

  01 function filterDOM (searchString) {

  02 const parsedSearchString = searchString andand searchString.toLowerCase() ;

  03 document.quesrySelectorAll(` .account' ) . forEach(account => (

  04 const accountName = account.innerHTML.toLOwerCase(); 05 account. Style.display = accountName.includes(parsedSearchString) ? /*Insert code*/;

  06 )};

  07 }

  Which code should replace the placeholder comment on line 05 to hide accounts that do not match thesearch string?

  A. ` name ' : ` block '
  B. ` Block ' : ` none '
  C. ` visible ' : ` hidden '
  D. ` hidden ' : ` visible '
  B. ` Block ' : ` none '

• Question 3:

  Refer to code below:

  Const objBook = {

  Title: `Javascript',

  };

  Object.preventExtensions(objBook);

  Const newObjBook = objBook;

  newObjectBook.author = `Robert';

  What are the values of objBook and newObjBook respectively?

  A. [title: "javaScript"] [title: "javaScript"]
  B. {author: "Robert", title: "javaScript} Undefined
  C. {author: "Robert", title: "javaScript} {author: "Robert", title: "javaScript}
  D. {author: "Robert"} {author: "Robert", title: "javaScript}
  A. [title: "javaScript"] [title: "javaScript"]

• Question 4:

  is below:

  

  The JavaScript portion is:

  01 function previewFile(){

  02const preview = document.querySelector(`img');

  03 const file = document.querySelector(`input[type=file]').files[0];

  04 //line 4 code

  05 reader.addEventListener("load", () => {

  06 preview.src = reader.result;

  07 },false);

  08 //line 8 code

  09 }

  In lines 04 and 08, which code allows the user to select an image from their local computer , and to display the image in the browser?

  A. 04 const reader = new File(); 08 if (file) URL.createObjectURL(file);
  B. 04 const reader = new FileReader(); 08 if (file) URL.createObjectURL(file);
  C. 04 const reader = new File(); 08 if (file) reader.readAsDataURL(file);
  D. 04 const reader = new FileReader(); 08 if (file) reader.readAsDataURL(file);
  D. 04 const reader = new FileReader(); 08 if (file) reader.readAsDataURL(file);

• Question 5:

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

• Question 6:

  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.
  D. Primitive values are immutable.

• Question 7:

  Which two console logs outputs NaN ?

  Choose 2 answers

  A. console.log(10/ Number(`5'));
  B. console.log(parseInt(`two'));
  C. console.log(10/ `'five);
  D. console.log(10/0);
  B. console.log(parseInt(`two'));
  C. console.log(10/ `'five);

• Question 8:

  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
  B. canTalk
  C. Type
  E. Size

• Question 9:

  Refer to the code below:

  Async funct on functionUnderTest(isOK) {

  If (isOK) return `OK' ;

  Throw new Error(`not OK');

  )

  Which assertion accurately tests the above code?

  A. Console.assert (await functionUnderTest(true), ` OK ')
  B. Console.assert (await functionUnderTest(true), ` not OK ')
  C. Console.assert (awaitfunctionUnderTest(true), ` not OK ')
  D. Console.assert (await functionUnderTest(true), `OK')
  D. Console.assert (await functionUnderTest(true), `OK')

• Question 10:

  Given the code below:

  const copy = JSON.stringify([ newString(` false '), new Bollean( false ), undefined ]);

  What is the value of copy?

  A. -- [ \"false\" , { } ]-
  B. -- [ false, { } ]-
  C. -- [ \"false\" , false, undefined ]-
  D. -- [ \"false\" ,false, null ]-
  D. -- [ \"false\" ,false, null ]-