[Aug-2026 Newly Released] JavaScript-Developer-I Dumps for Salesforce Developer Certified
Updated Verified JavaScript-Developer-I dumps Q&As - 100% Pass
NEW QUESTION # 33
GIven a value, which three options can a developer use to detect if the value is NaN?
Choose 3 answers !
- A. Object.is(value, NaN)
- B. value ! == value
- C. Number.isNaN(value)
- D. value === Number.NaN
- E. value == NaN
Answer: C,E
NEW QUESTION # 34
Given the following code:
What is the logged by the first four log statements?
- A. 0 1 2 3
- B. 0 1 2 2
- C. 0 0 1 2
- D. 0 1 1 2
Answer: D
NEW QUESTION # 35
Corrected code:
function Person() {
this.firstName = " John " ;
}
Person.prototype = {
job: x = > " Developer "
};
const myFather = new Person();
const result = myFather.firstName + " " + myFather.job();
What is the value of result after line 10 executes?
- A. " John Developer "
- B. " undefined Developer "
- C. " John undefined "
- D. Error: myFather.job is not a function
Answer: A
Explanation:
The verified answer is A .
This constructor function runs when new Person() is called:
function Person() {
this.firstName = " John " ;
}
So this line:
const myFather = new Person();
creates an object like this:
{
firstName: " John "
}
Then the prototype is assigned a method named job:
Person.prototype = {
job: x = > " Developer "
};
Because myFather is created from Person, it can access properties and methods from Person.prototype.
So:
myFather.firstName
returns:
" John "
And:
myFather.job()
returns:
" Developer "
Therefore:
const result = myFather.firstName + " " + myFather.job();
becomes:
const result = " John " + " " + " Developer " ;
Final value:
" John Developer "
Option B is incorrect because job() returns " Developer " , not undefined.
Option C is incorrect because job exists on Person.prototype, so it is callable.
Option D is incorrect because firstName is assigned inside the constructor.
Therefore, the verified answer is A .
NEW QUESTION # 36
Given the requirement to refactor the code above to JavaScript class format, which class definition is correct?
- A. A
- B. C
- C. D
- D. B
Answer: A
NEW QUESTION # 37
for (let number = 2; number < = 5; number += 1) {
// faster code statement here
}
Which statement meets the requirements to log an error when the Boolean statement evaluates to false?
- A. assert(number + 2 === 0);
- B. console.classy(number + 2 === 0);
- C. console.assert(number + 2 === 0);
- D. console.error(number + 2 === 0);
Answer: C
Explanation:
* console.assert(condition, message?) logs an assertion error if condition is falsy.
* To log an error when number + 2 === 0 is false, use:
console.assert(number + 2 === 0);
Other options are invalid or do not behave as described: console.error always logs, assert alone is not a built- in browser global, and console.classy doesn't exist.
NEW QUESTION # 38
Which three options show valid methods for creating a fat arrow function?
Choose 3 answers
- A. (x,y,z) => ( console.log(' executed ') ;)
- B. x => ( console.log(' executed ') ; )
- C. ( ) => ( console.log(' executed ') ;)
- D. [ ] => ( console.log(' executed ') ;)
- E. X,y,z => ( console.log(' executed ') ;)
Answer: A,B
NEW QUESTION # 39
Refer to the following code:
What is the output of line 11?
- A. ["foo", "bar"]
- B. [1,2]
- C. ["foo:1", "bar:2"]
- D. ["bar", "foo"]
Answer: A
NEW QUESTION # 40
A developer has the following array of hourly wages:
Let arr = (8, 5, 9, 75, 11, 25, 7, 75, , 13, 25);
For workers making less than $10 an hour rate should be multiple by 1.25 and returned in a new array.
How should the developer implement the request?
- A. let arrl = arr-map((num) => { return ran * 1.25 }).filter((val) -> { return val < 10));
- B. let arrl = arr.filter((val) => val < 10).map((num) -> num = 1.25);
- C. let arrl = arr .rr.acArray ((val) => ( val < 10 )) ,map((num) => { num * 1.25 ));
- D. let arrl = arr.filterBy((val) => val < 10 ).aapBy<(num) -> num = ..25 );
Answer: A
NEW QUESTION # 41
A team that works on a big project uses npm to deal with projects dependencies.
A developer added a dependency does not get downloaded when they execute npm install.
Which two reasons could be possible explanations for this?
Choose 2 answers
- A. The developer added the dependency as a dev dependency, and
NODE_ENV is set to production. - B. The developer added the dependency as a dev dependency, and
NODE_ENV
Is set to production. - C. The developer missed the option --add when adding the dependency.
- D. The developer missed the option --save when adding the dependency.
Answer: A,B,D
NEW QUESTION # 42
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 array after the code executes?
- A. [1, 2, 3, 4, 4, 5, 4]
- B. [1,2, 3, 4, 5, 4, 4]
- C. [1, 2, 3, 4, 5, 4]
- D. [1, 2, 3, 5]
Answer: A
NEW QUESTION # 43
A developer removes the HTML class attribute from the checkout button, so now it is simply:
< button > Checkout < /button >
There is a test to verify the existence of the checkout button, however it looks for a button with class= " blue "
. The test fails because no such button is found.
Which type of test category describes this test?
- A. True positive
- B. False negative
- C. False positive
- D. True negative
Answer: C
Explanation:
Definitions in testing context (treating "positive" as "test reports a bug/failure"):
* True positive : System has a bug; test correctly fails.
* False positive : System is correct; test fails (reports a bug that isn't actually a bug).
* True negative : System has a bug; test correctly passes indicating "no success" in detection context (less common phrasing here).
* False negative : System has a bug; test incorrectly passes (missed bug).
Here:
* The real requirement , as stated, is to verify the existence of the checkout button .
* The button still exists ( < button > Checkout < /button > ), so the system behavior is correct regarding that requirement.
* The test, however, is checking for an overly specific condition (class= " blue " ), which is not actually part of the stated requirement.
* The test fails , saying there is a problem (no button with class= " blue " ), even though from the requirement standpoint, the checkout button is present.
So:
* No real bug concerning presence of checkout button.
* Test reports a failure # a false positive .
Therefore, the correct category is D, False positive.
NEW QUESTION # 44
There is a new requirement for a developer to implement a currPrice method that will return the current price of the item or sales..
What is the output when executing the code above
- A. 5080Uncaught ReferenceError:this,discount is undefined72
- B. 0
- C. 1
- D. 50Uncaught TypeError: saleItem,desrcription is not a function5080
Answer: B
NEW QUESTION # 45
Refer to the code:
Given the code above, which three properties are set for pet1? Choose 3 answers
- A. owner
- B. name
- C. type
- D. canTalk
- E. size
Answer: C,D,E
NEW QUESTION # 46
The developer has a function that prints "Hello" to an input name. To test this, thedeveloper created a function that returns "World". However the following snippet does not print " Hello World".
What can the developer do to change the code to print "Hello World" ?
- A. Change line 2 to console.log('Hello' , name() );
- B. Change line 5 to function world ( ) {
- C. Change line 9 to sayHello(world) ();
- D. Change line 7 to ) () ;
Answer: A
NEW QUESTION # 47
Given the code below:
let numValue = 1982;
Which three code segments result in a correct conversion from number to string?
- A. let strValue = String(numValue);
- B. let strValue = numValue.toString();
- C. let strValue = ' ' + numValue;
- D. let strValue = numValue.toText();
- E. let strValue = (String)numValue;
Answer: A,B,C
Explanation:
We want to convert the number 1982 to a string.
Check each option:
* A. numValue.toText()
* There is no standard toText() method on numbers.
* This will result in TypeError: numValue.toText is not a function.
* B. String(numValue);
* String() as a function converts its argument to a string.
* String(1982) returns " 1982 " .
* This is correct.
* C. ' ' + numValue;
* ' ' is a string; + with a string operand performs string concatenation.
* ' ' + 1982 # " 1982 " .
* This is a common shorthand for number-to-string conversion.
* D. numValue.toString();
* Number.prototype.toString() converts the number to its string representation.
* 1982..toString() or (1982).toString() returns " 1982 " .
* For the variable, numValue.toString() is valid: " 1982 " .
* E. (String)numValue;
* This is not valid JavaScript casting syntax; it is more like a C/Java-style cast.
* In JavaScript, that is parsed as a grouping expression (String) and then numValue; it does not convert numValue to a string.
Thus the correct answers are:
* B. String(numValue);
* C. ' ' + numValue;
* D. numValue.toString();
Relevant concepts: primitive type conversion, String() casting, .toString(), coercion via + with strings.
NEW QUESTION # 48
Refer to the following code:
<html lang="en">
<body>
<divonclick = "console.log('Outer message') ;">
<button id ="myButton">CLick me<button>
</div>
</body>
<script>
function displayMessage(ev) {
ev.stopPropagation();
console.log('Inner message.');
}
const elem = document.getElementById('myButton');
elem.addEventListener('click' , displayMessage);
</script>
</html>
What will the console show when the button is clicked?
- A. Inner message
- B. Outer messageInner message
- C. Inner messageOuter message
- D. Outer message
Answer: A
NEW QUESTION # 49
A developer wants to use a try...catch statement to catch any error that countSheep () may throw and pass it to a handleError () function.
What is the correct implementation of the try...catch?
A)
B)
C)
D)
- A. Option
- B. Option
- C. Option
- D. Option
Answer: B
NEW QUESTION # 50
Referto the code below:
new Promise((resolve, reject) => {
const fraction = Math.random();
if( fraction >0.5) reject("fraction > 0.5, " + fraction);
resolve(fraction);
})
.then(() =>console.log("resolved"))
.catch((error) => console.error(error))
.finally(() =>console.log(" when am I called?"));
When does Promise.finally on line 08 get called?
- A. When resolved and settled
- B. When rejected
- C. When resolved or rejected
- D. When resolved
Answer: C
NEW QUESTION # 51
Refer to the code below:
Considering the implementations of 'use strict' on line 04, which three statements describes the executes of the code? Choose 3 answers
- A. 'use strict' has an effect between line 04 and the end of the file.
- B. Line 05 throws an error.
- C. 'use strict' has an effect only on line 05.
- D. 'use strict , is hoisted, so it has an effect on all lines.
- E. Z is equal to 3,14.
Answer: B,D,E
NEW QUESTION # 52
Refer to the code below:
Const pi w 3.1415926;
What is the data type of pi?
- A. Number
- B. Float
- C. Decimal
- D. Double
Answer: A
NEW QUESTION # 53
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Earning the Salesforce JavaScript-Developer-I certification can open up many career opportunities for developers, as it demonstrates their expertise in building custom solutions on the Salesforce platform. It can also lead to higher salaries and increased job satisfaction, as well as recognition from peers and employers.
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