JS-Dev-101 무료 덤프문제 온라인 액세스

A developer publishes a new version of a package with new features that do not break backward compatibility. The previous version number was 1.1.3.
Following semantic versioning formats, what should the new package version number be?

• A.2.0.0
• B.1.2.3
• C.1.1.4
• D.1.2.0

A developer copied a JavaScript object:
01 function Person() {
02 this.firstName = "John";
03 this.lastName = "Doe";
04 this.name = () => `${this.firstName},${this.lastName}`;
05 }
06
07 const john = new Person();
08 const dan = Object.assign({}, john);
09 dan.firstName = 'Dan';
How does the developer access dan's firstName, lastName?

• A.dan.name
• B.dan.name()
• C.dan.firstName() + dan.lastName()
• D.dan.firstName + dan.lastName

A class was written to represent items for purchase in an online store, and a second class representing items that are on sale at a discounted price. The constructor sets the name to the first value passed in. There is a new requirement for a developer to implement a description method that will return a brief description for Item and SaleItem.
01 let regItem = new Item('Scarf', 55);
02 let saleItem = new SaleItem('Shirt', 80, .1);
03 Item.prototype.description = function() { return 'This is a ' + this.name; }
04 console.log(regItem.description());
05 console.log(saleItem.description());
06
07 SaleItem.prototype.description = function() { return 'This is a discounted ' + this.name; } What is the output when executing the code above?

• A.This is a Scarf
  Uncaught TypeError: saleItem.description is not a function
  This is a Scarf
  This is a discounted Shirt
• B.This is a Scarf
  This is a Shirt
  This is a Scarf
  This is a discounted Shirt
• C.This is a Scarf
  This is a Shirt
  This is a discounted Scarf
  This is a discounted Shirt
• D.This is a Scarf
  Uncaught TypeError: saleItem.description is not a function
  This is a Shirt
  This is a discounted Shirt

Refer to the code below:
const pi = 3.1415926;
What is the data type of pi?

• A.Decimal
• B.Number
• C.Float
• D.Double

Given the code below:
01 function Person() {
02 this.firstName = 'John';
03 }
04
05 Person.proto = {
06 job: x => 'Developer'
07 });
08
09 const myFather = new Person();
10 const result = myFather.firstName + ' ' + myFather.job();
What is the value of result when line 10 executes?

• A.Error: myFather.job is not a function
• B.John Developer
• C.undefined Developer
• D.John undefined