[2023] Earn Quick And Easy Success With JavaScript-Developer-I Dumps
Free JavaScript-Developer-I pdf Files With Updated and Accurate Dumps Training
NEW QUESTION # 81
A developer is creating a simple webpage with a button. When a user clicks this button
for the first time, a message is displayed.
The developer wrote the JavaScript code below, but something is missing. The
message gets displayed every time a user clicks the button, instead of just the first time.
01 function listen(event) {
02 alert ( 'Hey! I am John Doe') ;
03 button.addEventListener ('click', listen);
Which two code lines make this code work as required?
Choose 2 answers
- A. On line 04, use event.stopPropagation ( ),
- B. On line 06, add an option called once to button.addEventListener().
- C. On line 02, use event.first to test if it is the first execution.
- D. On line 04, use button.removeEventListener(' click" , listen);
Answer: B,D
NEW QUESTION # 82
Given the following code:
document.body.addEventListener(' click ', (event) => {
if (/* CODE REPLACEMENT HERE */) {
console.log('button clicked!');
)
});
Which replacement for the conditional statement on line 02 allows a developer to correctly determine that a button on page is clicked?
- A. Event.clicked
- B. button.addEventListener('click')
- C. e.nodeTarget ==this
- D. event.target.nodeName == 'BUTTON'
Answer: D
NEW QUESTION # 83
Refer to the following object:
How can a developer access the fullname property for cat?
- A. Cat.fullName
- B. Cat.fullname ( )
- C. Cat.function.fullName
- D. Cat,get,fullname
Answer: D
NEW QUESTION # 84
Refer to the following code:
What is the output of line 11?
- A. [1,2]
- B. ["bar", "foo"]
- C. ["foo", "bar"]
- D. ["foo:1", "bar:2"]
Answer: C
NEW QUESTION # 85
The developer wants to test the array shown:
const arr = Array(5).fill(0)
Which two tests are the most accurate for this array ?
Choose 2 answers:
- A. console.assert( arr.length === 5 );
- B. arr.forEach(elem => console.assert(elem === 0)) ;
- C. console.assert (arr.length >0);
- D. console.assert(arr[0] === 0 && arr[ arr.length] === 0);
Answer: A,B
NEW QUESTION # 86
Which javascript methods can be used to serialize an object into a string and deserialize a JSON string into an object, respectively?
- A. JSON.parse and JSON.deserialize
- B. JSON.serialize and JSON.deserialize
- C. JSON.stringify and JSON.parse
- D. JSON.encode and JSON.decode
Answer: C
NEW QUESTION # 87
Which statement accurately describes the behavior of the async /swait keywords?
- A. The associated class contains some asynchronous functions.
- B. The associated function sometimes returns a promise.
- C. The associated function can only be called via asynchronous methods.
- D. The associated function will always return a promise.
Answer: D
NEW QUESTION # 88
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 missed the option --add when adding the dependency.
- C. The developer added the dependency as a dev dependency, and
NODE_ENV is set to production. - D. The developer missed the option --save when adding the dependency.
Answer: A,C,D
NEW QUESTION # 89
A developer wants to create an object from a function in the browser using the code below.
What happens due to lack of the new keyword on line 02?
- A. The n variable is assigned the correct object but this- remains undefined.
- B. The a variable is assigned the correct object.
- C. Window. n is assigned the correct object.
- D. Window. === name is assigned to ''hello'' and the variable a n remain undefined.
Answer: D
NEW QUESTION # 90
Refer to the code below:
Which value can a developer expect when referencing country,capital,cityString?
- A. undefined
- B. An error
- C. 'London'
- D. 'NaN'
Answer: D
NEW QUESTION # 91
Refer to HTML below:
<div id ="main">
<div id = " card-00">This card is smaller.</div>
<div id = "card-01">The width and height of this card is determined by its contents.</div>
</div>
Which expression outputs the screen width of the element with the ID card-01?
- A. document.getElementById(' card-01 ').getBoundingClientRest().width
- B. document.getElementById(' card-01 ').style.width
- C. document.getElementById(' card-01 ').width
- D. document.getElementById(' card-01 ').innerHTML.lenght*e
Answer: A
NEW QUESTION # 92
A developer wants to iterate through an array of objects and count the objects and count
the objects whose property value, name, starts with the letter N.
Const arrObj = [{"name" : "Zach"} , {"name" : "Kate"},{"name" : "Alise"},{"name" : "Bob"},{"name" :
"Natham"},{"name" : "nathaniel"}
Refer to the code snippet below:
01 arrObj.reduce(( acc, curr) => {
02 //missing line 02
02 //missing line 03
04 ). 0);
Which missing lines 02 and 03 return the correct count?
- A. Const sum = curr.startsWith('N') ? 1: 0;
Return acc +sum - B. Const sum = curr.name.startsWIth('N') ? 1: 0;
Return curr+ sum - C. Const sum = curr.name.startsWith('N') ? 1: 0;
Return acc +sum - D. Const sum = curr.startsWIth('N') ? 1: 0;
Return curr+ sum
Answer: C
NEW QUESTION # 93
A developer implements and calls the following code when an application state change occurs:
If the back button is clicked after this method is executed, what can a developer expect?
- A. A popstate event is fired with a state properly that details the application's last state.
- B. The page reloads and all JavaScript is reinitialized.
- C. A navigate event is fired with a state properly that details previous application state.
- D. The page is navigated away from and previous page in the browser's history is loaded.
Answer: D
NEW QUESTION # 94
is below:
<input type="file" onchange="previewFile()">
<img src="" height="200" alt="Image Preview..."/>
The JavaScript portion is:
01 function previewFile(){
02 const 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 FileReader();
08 if (file) URL.createObjectURL(file); - B. 04 const reader = new File();
08 if (file) reader.readAsDataURL(file); - C. 04 const reader = new FileReader();
08 if (file) reader.readAsDataURL(file); - D. 04 const reader = new File();
08 if (file) URL.createObjectURL(file);
Answer: C
NEW QUESTION # 95
A developer has code that calculates a restaurant bill, but generates incorrect answers 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. Wrapping findSubtotal in a console.log() method.
- C. Calling the console.trace (total) method on line 03.
- D. Using the debugger command on line 03
Answer: A
NEW QUESTION # 96
A developer is leading the creation of a new web server for their team that will fulfill API requests from an existing client.
The team wants a web server that runs on Node.Js, and they want to use the new web framework Minimalist.Js. The lead developer wants to advocate for a more seasoned back-end framework that already has a community around it.
Which two frameworks could the lead developer advocate for?
Choose 2 answers
- A. Koa
- B. Express
- C. Gatsby
- D. Angular
Answer: C,D
NEW QUESTION # 97
A developer wants to iterate through an array of objects and count the objects and count the objects whose property value, name, starts with the letter N.
Const arrObj = [{"name" : "Zach"} , {"name" : "Kate"},{"name" : "Alise"},{"name" : "Bob"},{"name" :
"Natham"},{"name" : "nathaniel"}
Refer to the code snippet below:
01 arrObj.reduce(( acc, curr) => {
02 //missing line 02
02 //missing line 03
04 ). 0);
Which missing lines 02 and 03 return the correct count?
- A. Const sum = curr.startsWith('N') ? 1: 0;
Return acc +sum - B. Const sum = curr.name.startsWIth('N') ? 1: 0;
Return curr+ sum - C. Const sum = curr.name.startsWith('N') ? 1: 0;
Return acc +sum - D. Const sum = curr.startsWIth('N') ? 1: 0;
Return curr+ sum
Answer: C
NEW QUESTION # 98
Refer to the code below:
What is display when the cod executes?
- A. ReferenceError: b is not defined
- B. Undefined
- C. null
- D. A
Answer: D
NEW QUESTION # 99
Refer to the expression below:
Let x = ('1' + 2) == (6 * 2);
How should this expression be modified to ensure that evaluates to false?
- A. Let x = ('1' + ' 2') == ( 6 * 2);
- B. Let x = (1 + 2 ) == ( 6 / 2);
- C. Let x = ('1' + 2) == ( 6 * 2);
- D. Let x = (1 + 2) == ( '6' / 2);
Answer: C
NEW QUESTION # 100
Refer to 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
- B. When rejected
- C. When resolved or rejected
- D. When resolved and settled
Answer: C
NEW QUESTION # 101
Refer to code below:
Let a ='a';
Let b;
// b = a;
console.log(b);
What is displayed when the code executes?
- A. A
- B. ReferenceError: b is not defined
- C. Undefined
- D. Null
Answer: C
NEW QUESTION # 102
A developer wrote the following code to test a sum3 function that takes in an array of numbers and returns the sum of the first three numbers in the array, and the test passes.
A different developer made changes to the behavior of sum3 to instead sum only the first two numbers present in the array.
Which two results occur when running this test on the updated sum3 function?
Choose 2 answers
- A. The line 05 assertion passes.
- B. The line 02 assertion passes.
- C. The line 02 assertion fails.
- D. The line 05 assertion fails.
Answer: B,D
NEW QUESTION # 103
Refer to the code below:
Const searchTest = 'Yay! Salesforce is amazing!" ;
Let result1 = searchText.search(/sales/i);
Let result 21 = searchText.search(/sales/i);
console.log(result1);
console.log(result2);
After running this code, which result is displayed on the console?
- A. > 5 > 0
- B. > 5 >undefined
- C. > true > false
- D. > 5 > -1
Answer: B
NEW QUESTION # 104
Which code statement correctly retrieves and returns an object from localStorage?
- A. const retrieveFromLocalStorage = () =>{
return JSON.stringify(window.localStorage.getItem(storageKey));
} - B. const retrieveFromLocalStorage = (storageKey) =>{
return window.localStorage.getItem(storageKey);
} - C. const retrieveFromLocalStorage = (storageKey) =>{
return window.localStorage[storageKey];
} - D. const retrieveFromLocalStorage = (storageKey) =>{
return JSON.parse(window.localStorage.getItem(storageKey));
}
Answer: D
NEW QUESTION # 105
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