JavaScript-Developer-I Exam - Salesforce Certified JavaScript Developer I

NEW QUESTION 1
Refer to the code below: const addBy = ?
const addByEight =addBy(8); const sum = addBYEight(50);
Which two functions can replace line 01 and return 58 to sum? Choose 2 answers

• A. const addBy = function(num1){ return function(num2){return num1 + num2;}
• B. const addBy = function(num1){ return num1 + num2;}
• C. const addBy = (num1) => num1 + num2 ;
• D. const addBY = (num1) => (num2) => num1 + num2;

Answer: AD

NEW QUESTION 2
Refer to the code below:
Async funct on functionUnderTest(isOK) { If (isOK) return ‘OK’ ;
Throw new Error(‘not OK’);
)
Which assertion accuretely 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’)

Answer: D

NEW QUESTION 3
A developer has an ErrorHandler module that contains multiple functions. What kind of export be leverages sothat multiple functions can be used?

• A. Named
• B. All
• C. Multi
• D. Default

Answer: A

NEW QUESTION 4
Refer to code below:

What is displayed when the code executes?

• A. ReferenceError: b is not defined
• B. a
• C. Undefined
• D. Null

Answer: C

Explanation:

NEW QUESTION 5
A developer is leading the creation of a new browser application that will serve a single page application. The teamwants to use a new web framework Minimalsit.js. The Lead developer wants to advocate for a more seasoned web framework that already has a community around it.
Which two frameworks should the lead developer advocate for? Choose 2 answers

• A. Vue
• B. Angular
• C. Koa
• D. Express

Answer: BD

NEW QUESTION 6
Refer to code below:

What are the values for first and second once the code executes ?

• A. First is Who and second is When
• B. First is why and second is where
• C. First is who and second is where
• D. First is why andsecond is when

Answer: D

NEW QUESTION 7
A developer implements a function that adds a few values.

Which three options can the developer invoke for this function to get a return value of 10 ? Choose 3 answers

• A. Sum () (20)
• B. Sum (5, 5) ()
• C. sum() (5, 5)
• D. sum(5)(5)
• E. sum(10) ()

Answer: CD

NEW QUESTION 8
A developer has the function, shown below, that is called when a page loads.

Where can the developer see the log statement after loading the page in the browser?

• A. Terminal running the web server.
• B. Browser performance toots
• C. Browser javaScript console
• D. On the webpage.

Answer: C

NEW QUESTION 9
developer is trying to convince management that their team will benefit from using
Node.js for a backend server that they are going to create. The server will be a web server that handles API requests from a website that the team has already built using HTML, CSS, and JavaScript.
Which three benefits of Node.js can the developer use to persuade their manager? Choose 3 answers:

• A. I nstalls with its own package manager toinstall and manage third-party libraries.
• B. Ensures stability with one major release every few years.
• C. Performs a static analysis on code before execution to look for runtime errors.
• D. Executes server-side JavaScript code to avoid learning a new language.
• E. User non blocking functionality for performant request handling .

Answer: ACE

NEW QUESTION 10
Refer to the code snippet below:
Let array = [1, 2, 3, 4,4, 5, 4, 4];
For (let i =0; i < array.length; 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]

Answer: C

NEW QUESTION 11
Refer to the HTML below:
<div id=”main”>
<ul>
<li>Leo</li>
<li>Tony</li>
<li>Tiger</li>
</ul>
</div>
Which JavaScript statementresults in changing “ Tony” to “Mr. T.”?

• A. document.querySelectorAll(‘$main $TONY’).innerHTML = ’ M
• B. ’;
• C. document.querySelector(‘$main li:second-child’).innerHTML = ’ M
• D. ’;
• E. document.querySelector(‘$main li.Tony’).innerHTML = ’ M
• F. ’;
• G. document.querySelector(‘$main li:nth-child(2)’),innerHTML = ’ M
• H. ’;

Answer: D

NEW QUESTION 12
Refer to the code below:
Let inArray =[ [ 1, 2 ] , [ 3, 4, 5 ] ];
Which two statements result in the array [1, 2, 3, 4, 5] ?
Choose 2 answers

• A. [ ]. Concat.apply ([ ], inArray);
• B. [ ]. Concat (... inArray);
• C. [ ]. concat.apply(inArray, [ ]);
• D. [ ]. concat ( [ ….inArray ] );

Answer: AB

NEW QUESTION 13
Which statement phrases successfully?

• A. JSON.parse ( ‘ foo ’ );
• B. JSON.parse ( “ foo ” );
• C. JSON.parse( “ ‘ foo ’ ” );
• D. JSON.parse(‘ “ foo ” ’);

Answer: D

NEW QUESTION 14
Refer to the code below:

After running this code, which result is displayed on the console?

• A. > true > false
• B. > 5 >undefined
• C. > 5 > -1
• D. >5 > 0

Answer: B

Explanation:

NEW QUESTION 15
Referto the code below: Const pi = 3.1415326, What is the data type of pi?

• A. Double
• B. Number
• C. Decimal
• D. Float

Answer: B

NEW QUESTION 16
Refer to the following code that performs a basic mathematical operation on a provided input:
function calculate(num) { Return (num +10) / 3;
}
How should line 02 be written to ensure thatx evaluates to 6 in the line below? Let x = calculate (8);

• A. Return Number((num +10) /3 );
• B. Return (Number (num +10 ) / 3;
• C. Return Integer(num +10) /3;
• D. Return Number(num + 10) / 3;

Answer: B

NEW QUESTION 17
Which option is true about the strict mode in imported modules?

• A. Add the statement use non-strict, before any other statements in the module to enable not-strict mode.
• B. You can only reference notStrict() functions from the imported module.
• C. Imported modules are in strict mode whether you declare them as such or not.
• D. Add the statement use strict =false; before any other statements in the module to enable not- strict mode.

Answer: B

NEW QUESTION 18
A developer has code that calculates a restaurant bill, but generates incorrectanswers while testing the code:
function calculateBill ( items ) { let total = 0;
total += findSubTotal(items); total += addTax(total);
total += addTip(total); return total;
}
Which option allows the developer to step into each function execution within calculateBill?

• A. Using the debugger command on line 05.
• B. Using the debugger command on line 03
• C. Calling the console.trace (total) method on line 03.
• D. Wrapping findSubtotal in a console.log() method.

Answer: A

NEW QUESTION 19
GIven a value, which three options can a developer use to detect if the value is NaN? Choose 3 answers !

• A. value == NaN
• B. Object.is(value, NaN)
• C. value === Number.NaN
• D. value ! == value
• E. Number.isNaN(value)

Answer: AE

NEW QUESTION 20
Refer to the code below: Let textValue = ’1984’;
Which code assignment shows a correct way to convert this string to an integer?

• A. let numberValue = Number(textValue);
• B. Let numberValue = (Number)textValue;
• C. Let numberValue = textValue.toInteger();
• D. Let numberValue = Integer(textValue);

Answer: A

NEW QUESTION 21
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