JS-Dev-101 무료 덤프문제 온라인 액세스

A developer is required to write a function that calculates the sum of elements in an array but is getting undefined every time the code is executed. The developer needs to find what is missing in the code below.
01 const sumFunction = arr => {
02 return arr.reduce((result, current) => {
03 //
04 result += current;
05 //
06 }, 10);
07 };
Which line replacement makes the code work as expected?

• A.03 if(arr.length == 0) { return 0; }
• B.05 return result;
• C.02 arr.map((result, current) => {
• D.04 result = result + current;

What are two unique features of fat-arrow functions compared to normal function definitions?

• A.The function receives an argument called parentThis, giving the enclosing lexical scope.
• B.The function uses the this from the enclosing scope.
• C.The function generates its own this making it useful for separating scope.
• D.If the function has a single expression in the function body, the expression will be evaluated and implicitly returned.

A developer creates a new web server that uses Node.js. It imports a server library that uses events and callbacks for handling server functionality. The server library is imported with require and is made available to the code by a variable named server. The developer wants to log any issues that the server has while booting up.
Which code logs an error at boot time with an event?

• A.server.error((error) => {
  console.log('ERROR', error);
  });
• B.server.on('error', (error) => {
  console.log('ERROR', error);
  });
• C.server.catch((error) => {
  console.log('ERROR', error);
  });
• D.try {
  server.start();
  } catch(error) {
  console.log('ERROR', error);
  }

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?

• A.Gatsby
• B.Angular
• C.Next
• D.Next.js

Refer to the following code (correcting the missing template literal backticks):
let codeName = 'Bond';
let sampleText = `The name is ${codeName}, Jim ${codeName}`;
A developer is trying to determine if a certain substring is part of a string.
Which three code statements return true?

• A.sampleText.includes('The', 1);
• B.sampleText.indexOf('Bond') !== -1;
• C.sampleText.includes('Jim', 4);
• D.sampleText.includes('Jim');
• E.sampleText.substring('Jim');