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

質問 1

Refer to the followingcode:

（A）Inner message
Outer message

（B）Outer message
Inner message

（C）Button message

（D）Outer message

正解：C 解答を投票する

質問 2

Given the following code:
Let x =null;
console.log(typeof x);
What is the output of the line 02?

（A）"Object"

（B）"undefined"

（C）"X"

（D）"Null"

正解：A 解答を投票する

質問 3

Given code below:
setTimeout (()=> (
console.log(1);
). 0);
console.log(2);
New Promise ((resolve, reject )) = > (
setTimeout(() => (
reject(console.log(3));
). 1000);
)).catch(() => (
console.log(4);
));
console.log(5);
What is logged to the console?

（A）2 5 1 3 4

（B）1 2 5 3 4

（C）1 2 43 5

（D）2 1 4 3 5

正解：A 解答を投票する

質問 4

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 teamhas 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）Uses non-blocking functionality for performant requesthandling .

（B）Ensures stabilitywith one major release every few years.

（C）Executes server-side JavaScript code to avoid learning a new language.

（D）Performs a static analysis on code before execution to look for runtime errors.

（E）Installs with its own package manager to install and manage third-party libraries.

正解：A、D、E 解答を投票する

質問 5

Which option is a core Node,js module?

（A）Ios

（B）Memory

（C）locate

（D）Path

正解：D 解答を投票する

質問 6

Which two console logs outputs NaN ?
Choose 2 answers

（A）console.log(10/0);

（B）console.log(10/ ''five);

（C）console.log(parseInt('two'));

（D）console.log(10/ Number('5'));

正解：B、C 解答を投票する

質問 7

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）

正解：C 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

A developer uses a parsed JSON string to work with user information as in the block below:
01 const userInformation ={
02 " id " : "user-01",
03 "email" : "[email protected]",
04 "age" : 25
Which two options access the email attribute in the object?
Choose 2 answers

（A）userInformation(email)

（B）userInformation("email")

（C）userInformation.email

（D）userInformation.get("email")

正解：B、C 解答を投票する

質問 10

Refer to thefollowing code that imports a module named utils:
import (foo, bar) from '/path/Utils.js';
foo() ;
bar() ;
Which two implementations of Utils.js export foo and bar such that the code above runs without error?
Choose 2 answers

（A）const foo = () => { return 'foo';}const bar = () => {return 'bar'; }Export default foo, bar;

（B）Export default class {foo() { return 'foo' ; }bar() { return 'bar' ; }}

（C）// FooUtils.js and BarUtils.js existImport (foo) from '/path/FooUtils.js';Import (boo) from '
/path/NarUtils.js';

（D）const foo = () => { return 'foo' ; }const bar = () => { return 'bar' ; }export { bar, foo }

正解：B、D 解答を投票する

質問 11

A developer is setting up a new Node.js server with a client library that is built using events and callbacks.
The library:
Will establish a web socket connection and handle receipt of messages to theserver Will be imported with require, and made available with a variable called we.
The developer also wants to add error logging if a connection fails.
Given this info, which code segment shows the correct way to set up a client with two events that listen at execution time?

（A）ws.connect (( ) => {console.log('connected to client'); }).catch((error) => { console.log('ERROR' , error); }};

（B）ws.on ('connect', ( ) => { console.log('connected to client'); }}; ws.on('error', (error) => { console.log('ERROR' , error); }};

（C）ws.on ('connect', ( ) => {console.log('connected to client'); ws.on('error', (error) => { console.log('ERROR' ,error); });});

（D）try{ws.connect (( ) => {console.log('connected to client'); });} catch(error) { console.log('ERROR',error); };}

正解：C 解答を投票する

質問 12

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 13

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 14

A developer wants to define a function log to be used a few times on a single-file JavaScript script.
01 // Line 1 replacement
02 console.log('"LOG:', logInput);
03 }
Which two options can correctly replaceline 01 and declare the function for use?
Choose 2 answers

（A）const log(loginInput) {

（B）function leg(logInput) {

（C）const log = (logInput) => {

（D）function log = (logInput) {

正解：B、C 解答を投票する

質問 15

A developer needs to debug a Node.js web server because a runtime error keeps occurring at one of the endpoints.
The developer wants to test the endpoint on a local machine and make the request against a local server to look at the behavior. In the source code, the server, js file will start the server. the developer wants to debug the Node.js server only using the terminal.
Which command can the developer use to open the CLI debugger in their current terminal window?

（A）node server,js inspect

（B）node start inspect server,js

（C）node -i server.js

（D）node inspect server,js

正解：D 解答を投票する

質問 16

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, 5]

（B）[1,2, 3, 4, 5, 4, 4]

（C）[1, 2, 3, 4, 5, 4]

（D）[1, 2, 3, 4, 4, 5, 4]

正解：D 解答を投票する

質問 17

Refer to the following code:

What is the output of line 11?

（A）["foo", "bar"]

（B）["bar", "foo"]

（C）[1,2]

（D）["foo:1", "bar:2"]

正解：A 解答を投票する

質問 18

Given the JavaScript below:

Which code should replace the placeholder comment on line 05 to highlight accounts that match the search string'

（A）'yellow : 'none'

（B）'yellow' : null

（C）'none1 : "yellow'

（D）null : 'yellow'

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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