ES6 (146)

What keyword is used to define class member that are referenced on the class directly rather than on instances of the class?

 protected

 static

 extends

 implements

Is super() required in child's class even if it doesn't implement constructor?

 yes

 no

What will the following code output to the console?

class Parent {
    constructor() {
        console.log("created");
    }
}
class Child extends Parent {}
var a = new Child()

 created

 nothing

 throw an error

What will the following code output to the console?

class Car {
    constructor() {
        console.log("created");
    }
}
var car = new Car();

 created

 nothing

 throw an error

Which of the following function should be executed to reject a promise?

var x = new Promise(function (a, b) { 
});

 a

 b

Which of the following function should be executed to resolve a promise?

var x = new Promise(function (a, b) { 
});

 a

 b

Promise is in one of 3 states. Which one?

 ready

 pending

 rejected

 progress

 fulfilled

The Promise represents:

 the function declaration with the specified parameters

 a constructor that creates a new generator function object

 a shorter syntax for a function expression

 the eventual completion or failure of an asynchronous operation

What will the following code output to the console?

let isAsync = false;
function doAsync() {
  return new Promise(function (resolve, reject) {
    resolve();
  });
}

doAsync()
​​​​​​​.then(function (val) {
  console.log(isAsync);
});
isAsync = true;

 true

 false

What will the following code output to the console?

function doAsync() {
  return new Promise(function (resolve, reject) {
    reject();
  });
}

doAsync()
.then(function () {
  console.log(true);
})
​​​​​​​.catch(function () {
  console.log(false);
});

 true

 false

 true and then false

 false and then true