JavaScript-Developer-I無料問題集「Salesforce Certified JavaScript Developer I」

質問 1

Refer to the code below
let inArray = [[1,2],[3,4,5]];
which two statements results in the array [1,2,3,4,5]?
choose 2 answer

（A）[ ].concat.apply(inArray,[ ]);

（B）[ ].concat.apply([ ],inArray);

（C）[ ].concat(...inArray);

（D）[ ].concat([...inArray])

正解：B、C 解答を投票する

質問 2

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）Angular

（B）Gatsby

（C）Koa

（D）Express

正解：A、B 解答を投票する

質問 3

A developer has two ways to write a function:
Option A:
function Monster() {
This.growl = () => {
Console.log ("Grr!");
}
}
Option B:
function Monster() {};
Monster.prototype.growl =() => {
console.log("Grr!");
}
After deciding on an option, the developer creates 1000 monster objects.
How many growl methods are created with Option A Option B?

（A）1 growl method is created for Option A.1000 growl methods are created for Option B.

（B）1 growl method is created regardless of whichoption is used.

（C）1000 growl methods are created regardless of which option is used.

（D）1000 growl method is created for Option A. 1 growl methods are created for Option B.

正解：D 解答を投票する

質問 4

Refer to the code below:
Function changeValue(obj) {
Obj.value = obj.value/2;
}
Const objA = (value: 10);
Const objB = objA;
changeValue(objB);
Const result = objA.value;
What is the value of result after the code executes?

（A）Undefined

（B）5

（C）10

（D）Nan

正解：B 解答を投票する

質問 5

Given the expressionsvar1 and var2, what are two valid ways to return the concatenation of the two expressions and ensure it is string? Choose 2 answers

（A）String (var1) .concat (var2)

（B）var1 + var2

（C）string.concat (var1 +var2)

（D）var1.toString ( ) var2.toString ( )

正解：C、D 解答を投票する

質問 6

A developer implements and calls the following code when an application state change occurs:
Const onStateChange =innerPageState) => {
window.history.pushState(newPageState, ' ', null);
}
If the back button is clicked after this method is executed, what can a developer expect?

（A）The page reloads and all Javascript is reinitialized.

（B）A popstate event is fired with a state property that details the application's last state.

（C）The page isnavigated away from and the previous page in the browser's history is loaded.

（D）A navigate event is fired with a state property that details the previous application state.

正解：C 解答を投票する

質問 7

A developer at Universal Containers is creating their new landing page based on HTML, CSS, and JavaScript.
To ensure that visitors have a good experience, a script named personalizeWebsiteContent needs to be executed when the webpage is fully loaded (HTML content and all related files), in order to do some custom initializations.
Which implementation should be used to call Fe:s:-a;::eHec5;te::.-.ter.: based on the business requirement above?

（A）Add a handler to the personalizeWebsiteContent script to handle the load event

（B）Add a listener to thewindow object to handle the DOMContentLoaded event

（C）Add a handler to the personalizeWebsiteContent script tohandle the DOMContentLoaded event

（D）Add a listener to the window object to handle the lead event

正解：D 解答を投票する

質問 8

Which code statement below correctly persists an objects inlocal Storage ?

（A）const setLocalStorage = ( jsObject) => {window.localStorage.connectObject(jsObject));}

（B）const setLocalStorage= ( jsObject) => {window.localStorage.setItem(jsObject);}

（C）const setLocalStorage = (storageKey, jsObject) => {window.localStorage.setItem(storageKey, JSON.stringify(jsObject));}

（D）const setLocalStorage = (storageKey, jsObject) => {window.localStorage.persist(storageKey, jsObject);}

正解：C 解答を投票する

質問 9

Refer tothe code below:

What is the value of result after line 10 executes?

（A）undefined Developer

（B）John undefined

（C）John Developer

（D）Error: myFather.job is not a function

正解：C 解答を投票する

質問 10

Refer to the code below:

What is the output of this function when called with an empty array?

（A）Return 5

（B）Return 0

（C）Return Infinity

（D）Return NaN

正解：A 解答を投票する

質問 11

Refer to the code below:
function changeValue(param) {
Param =5;
}
Let a =10;
Let b =5;
changeValue(b);
Const result = a+ " - "+ b;
What is the value of result when code executes?

（A）5 -5

（B）5 - 10

（C）10 - 5

（D）10 -10

正解：D 解答を投票する

質問 12

Refer to the HTML below:
<div id="main">
<ul>
<li>Leo</li>
<li>Tony</li>
<li>Tiger</li>
</ul>
</div>
Which JavaScript statement results in changing " Tony" to "Mr. T."?

（A）document.querySelector('$main li:second-child').innerHTML = ' Mr. T. ';

（B）document.querySelector('$main li:nth-child(2)'),innerHTML =' Mr. T. ';

（C）document.querySelectorAll('$main $TONY').innerHTML = ' Mr. T. ';

（D）document.querySelector('$main li.Tony').innerHTML = ' Mr. T. ';

正解：B 解答を投票する

質問 13

Considering type coercion, what does the following expression evaluate to?
True + '13' + NaN

（A）14

（B）' true13 '

（C）' true13NaN '

（D）' 113Nan '

正解：C 解答を投票する

質問 14

Refer to the following array:
Let arr = [ 1,2, 3, 4, 5];
Which three options result in x evaluating as [3, 4, 5] ?
Choose 3 answers.

（A）Let x= arr.filter (( a) => (a<2));

（B）Letx= arr.filter((a) => ( return a>2 ));

（C）Let x= arr.splice(2,3);

（D）Let x= arr.slice(2);

（E）Let x = arr.slice(2,3);

正解：B、C、D 解答を投票する

質問 15

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 fora button with class= "blue". The test fails because no such button is found.
Which type of test category describes this test?

（A）False negative

（B）True negative

（C）True positive

（D）False positive

正解：A 解答を投票する

質問 16

Given the code below:
Setcurrent URL ();
console.log('The current URL is: ' +url );
functionsetCurrentUrl() {
Url = window.location.href:
What happens when the code executes?

（A）The url variable has global scope and line 02 executes correctly.

（B）The url variable has local scope and line 02 throws an error.

（C）The url variable has global scope and line 02 throws an error.

（D）The url variable has local scope and line 02 executes correctly.

正解：A 解答を投票する

JavaScript-Developer-I 無料問題集「Salesforce Certified JavaScript Developer I」

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