ECMAScript6 MCQs Solution | TCS Fresco Play | FrescoPlay | MNC Answers
Make an effort to understand these solutions and apply them to your Hands-On difficulties. (It is not advisable that copy and paste these solutions).
All Question of the MCQs Present Below for Ease Use Ctrl + F with the question name to find the Question. All the Best!
1. ECMAScript is a __________
Language Standard
2. ES6 is the implementation of?
ECMAScript
3. All major JavaScript Implementations are based on which standard?
ECMAScript
4. ES6 is officially called ______________
ECMA Script 2015
5. ES6 can be used for ______________
Both client side and server side scription
6. During destructuring, you can either declare variables or assign to them, or both.
FALSE
7. Which of the following parameters can be used to expand a single array into multiple arguments?
Spread
8. const { x, y } = { x: 11, y: 8 }; is the Same as const { x: x, y: y } = { x: 11, y: 8 };
TRUE
9. Destructuring helps us to extract multiple values from an object via __________.
Object Pattern
10. What will be the output of following code snippet?
function foo(a = 10, b = 5) {
console.log(a, b);
}
foo(6);
6,5
6,5
6,5
11. The following code implements the ______ feature of ES6 function myFunction(x, y, z) { } var args = [0, 1, 2]; myFunction(...args);
Spread
12. "Rest" collects all variables into a single array, while "Spread" expands a single variable into multiple.
TRUE
13. Which of the following parameters can be used to define indefinite number of parameters in one single array?
rest
14. Template literals does not allow us to _________.
None of the options
15. Which is not a lexical inside arrow functions?
None of the options
16. Variables declared in a scope are accessible in ___________.
All scopes nested inside it
17. In Arrow functions, if there is only one parameter and that parameter is an identifier then the parentheses can be omitted.
TRUE
18. Template literals support ____________.
interpolation
19. Template literals can be reused __________.
TRUE
20. const func= (
x,
y
) => {
return x + y;
};
func(11,12);
23
21. Select the wrong code Snippet
const func1 = (x, y) => { return x + y; };
22. Instead of using single quotes or double quotes, es6 uses BACKTICK or OPENQUOTE ( " ` " ) character to create destructuring pattern.
FALSE
23. Arrow Functions are less verbose than traditional functions.
TRUE
24. Template literals can be defined as _________.
multi-line string literals that support interpolation
25. Which keywords can be used to implement inheritance in ES6?
extends
26. We can use this data-type to avoid repetitions.
Sets
27. The bodies of class declarations and class expressions are executed in strict mode.
TRUE
28. class Player extends Student {
constructor(roll, name) {
super(roll, name);
this.Player = true;
}
};
Constructor of the Parent Class
29. _________ feature helps us to simplify the inheritance concept.
Classes
30. Maps can be used to store __________.
Key - value pairs
31. Map can use _______ value as Key.
Any
32. Which is not true about constructor in ES6?
A class may have any number of constrcutors
33. Which is not true about static methods?
Static methods can be directly called with the help of a class object.
34. Sets can be used to store __________.
Heterogeneous data
35. Objects declared as "const" are immutable.
FALSE
36. Which of the following does not declare a block scoped variable?
var
37. What is the significance of the following code snippet?
for (let i = 0; i < 10; i++) {
x += 10;
}
The variable i is valid only inside the for loop
38. Which of the following statements is not true about level of scope?
I. let keyword declares a block scoped variable.
II. var keyword declares a block scoped variable.
III. const keyword declares a block scoped variable.
IV. let and const are similiar to each other.
I & III are true and II and IV are false.
39. What is the scope of the variable "a" in function below?
function val(x){
if(x>0){
let a = x;
console.log(a);
}
}
Block
40. Keyword "let" allows redeclaring variables.
FALSE
41. Promise reactions are callbacks that you register with the Promise method then(), to be notified of a fulfillment or a rejection.
TRUE
42. What if promise2 get rejected in the following syntax? Promise.all(promise1, promise2, .....)
It will reject the entire set
43. Which of the following is not a state of Promise?
Approved
44. A Promise has _________ number of states.
3
45. Symbols can be created using the factory function _________.
Symbol()
46. Declaring variables with which of the following keywords, will make the variable immutable?
Const
47. What is the meaning of the following line of code?
const pi=3.14;
Const turns variables into constants, and they can’t be changed.
48. Variables declared with which of the following constructs do not have block scope?
var
49. What will be the output of this code?
var sym = new Symbol();
Syntax Error
50. What will be the output of following code snippet?
const cart =Object.freeze({ name: 'Dove', price: '4.50' });
cart.price = '5.10' ;
console.log(cart);
{name: 'dove',price '4,50'}
51. What will be printed if the following code is executed?
let x=150;
if(x>100)
{
x=1;
}
console.log(x);
1 (answer)
52. Which method can be used to retrieve symbols from the global symbols registry?
Symbol.KeyFor()
53. ES6 is the first time that JavaScript has built-in modules.
TRUE
54. Using yield(), Generators can receive input from _________.
next()
Post a Comment