es2015 quiz
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ES6 KingInteractive fun quiz about new generation of JavaScript for your front end developers that will make them sweat and swear
ES6 KingInteractive fun quiz about new generation of JavaScript for your front end developers that will make them sweat and swear
ES6 KingES2015
Interactive fun quiz about new generation of JavaScript for your front end developers that will make them sweat and swear
Rules4 teams
4 possible answers
1 minute per question
1 winner
The answer must be explained
12 questions
Rules4 teams
4 possible answers
1 minute per question
1 winner
The answer must be explained
12 questions
Rules4 teams
4 possible answers1 minute per question
1 winner
The answer must be explained
12 questions
Rules4 teams
4 possible answers
1 minute per question
1 winner
The answer must be explained
12 questions
Rules4 teams
4 possible answers
1 minute per question
1 winner
The answer must be explained
12 questions
Rules4 teams
4 possible answers
1 minute per question
1 winner
The answer must be explained
12 questions
Ready?Steady!Go!
01
Question01
let x = 42;
if (true) {
console.log(x);
let x = 1337;
}
What’s the result of the console.log operation?
1. 422. undefined3. Error4. 1337
let x = 42;
if (true) {
console.log(x);
let x = 1337;
}
What’s the result of the console.log operation?
1. 422. undefined3. Error4. 1337
01
Question02
var x = `foo ${y}`,
y = `bar ${x}`;
console.log(y);
What’s the result of this code?
1. bar foo bar undefined
2. bar foo undefined
3. bar foo4. InternalError
What’s the result of this code?
var x = `foo ${y}`,
y = `bar ${x}`;
console.log(y);
1. bar foo bar undefined
2. bar foo undefined
3. bar foo4. InternalError
01
Question03
What’s the result of this code?
1. 12. 33. [1,2,3]4. Error
((...x, xs)=>x)(1,2,3)
What’s the result of this code?
((...x, xs)=>x)(1,2,3)
1. 12. 33. [1,2,3]4. Error
01
Question04
(new function f () {
this.a = 1;
return ((...b) => {
return this.a;
}).bind({ a: 9 });
})();
What’s the result of this code?
1. 92. undefined3. TypeError4. 1
(new function f () {
this.a = 1;
return ((...b) => {
return this.a;
}).bind({ a: 9 });
})();
What’s the result of this code?
1. 92. undefined3. TypeError4. 1
01
Question05
let x, { x: y = 1 } = { x }; y;
What’s the result of this code?
1. undefined2. 1 3. {x: 1}4. Error
What’s the result of this code?
let x, { x: y = 1 } = { x }; y;
1. undefined2. 1 3. {x: 1}4. Error
01
Question06
typeof (function* f() {
yield f;
})().next()
What’s the result of this code?
1. “function”2. “generator”3. “object”4. Error
typeof (function* f() {
yield f;
})().next()
What’s the result of this code?
1. “function”2. “generator”3. “object”4. Error
01
Question07
class MyClass {
const MY_CONST = 'string';
constructor() {
this.MY_CONST;
}
}
let myClass = new MyClass();
console.log(myClass.MY_CONST);
What’s the result of this code?
1. ‘string’2. SyntaxError3. undefined4. ReferenceError
class MyClass {
const MY_CONST = 'string';
constructor() {
this.MY_CONST;
}
}
let myClass = new MyClass();
console.log(myClass.MY_CONST);
What’s the result of this code?
1. ‘string’2. SyntaxError3. undefined4. ReferenceError
01
Question08
function* g() {
return 1;
}
for (let i of g())
console.log(i);
What’s the result of this code?
1. 12. Error3. undefined4. [object Object]
function* g() {
return 1;
}
for (let i of g())
console.log(i);
What’s the result of this code?
1. 12. Error3. undefined4. [object Object]
01
Question09
let popo = (function*() {
console.log([yield, yield]);
}());
popo.next(1);
popo.next(2);
popo.next(3);
What’s the result of this code?
1. [1,2]2. [2,3]3. [1,undefined]4. Error
let popo = (function*() {
console.log([yield, yield]);
}());
popo.next(1);
popo.next(2);
popo.next(3);
What’s the result of this code?
1. [1,2]2. [2,3]3. [1,undefined]4. Error
01
Question10
What’s the result of this code?
1. f, f, f2. f, t, f3. f, t, t4. t, t, t
class X {}
class Y extends X {}
console.log(Object.getPrototypeOf(X) ===
Function.prototype);
console.log(Object.getPrototypeOf(Y) === X);
console.log(Object.getPrototypeOf(new Y()) ===
Y.prototype)
What’s the result of this code?
1. f, f, f2. f, t, f3. f, t, t4. t, t, t
class X {}
class Y extends X {}
console.log(Object.getPrototypeOf(X) ===
Function.prototype);
console.log(Object.getPrototypeOf(Y) === X);
console.log(Object.getPrototypeOf(new Y()) ===
Y.prototype)
01
Question11
What’s the result of this code?
1. []2. [2,3,4,5,1]3. [5,4,3,2,1]4. Error
let f = (x, ...y) => x?[...f(...y), x]:[];
let arr = [], i = 0;
for (arr[i++] of f(1,2,3,4,5)) {}
console.log(arr);
What’s the result of this code?
1. []2. [2,3,4,5,1]3. [5,4,3,2,1]4. Error
let f = (x, ...y) => x?[...f(...y), x]:[];
let arr = [], i = 0;
for (arr[i++] of f(1,2,3,4,5)) {}
console.log(arr);
01
Question12
What’s the result of this code?
1. [1,2]2. 33. 44. 5 let m = new Map([[1,2],[[1,2],3],[2,4],[3,5]]);
console.log(m.get([...m][1][1]));
What’s the result of this code?
1. [1,2]2. 33. 44. 5 let m = new Map([[1,2],[[1,2],3],[2,4],[3,5]]);
console.log(m.get([...m][1][1]));
And the winner is...
Thank Youcredits:
● Afonso Matos● Juriy Zaytsev● Dmitry Soshnikov
● Kim Gysen● Ben Katz● Sergey Bolshchikov