114. What will happen?
let config = {
alert: setInterval(() => {
console.log('Alert!');
}, 1000),
};
config = null;114. What will happen?
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Javob variantlari:
Anonymous Quiz
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A: The setInterval callback won't be invoked
0%
B: The setInterval callback gets invoked once
0%
C: The setInterval callback will still be called every second
0%
D: We never invoked config.alert(), config is null
115. Which method(s) will return the value 'Hello world!'?
const myMap = new Map();
const myFunc = () => 'greeting';
myMap.set(myFunc, 'Hello world!');
//1
myMap.get('greeting');
//2
myMap.get(myFunc);
//3
myMap.get(() => 'greeting');
115. Which method(s) will return the value 'Hello world!'?
Javob variantlari:
Javob variantlari:
Anonymous Quiz
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A: 1
0%
B: 2
0%
C: 2 and 3
0%
D: All of them
116. What's the output?
const person = {
name: 'Lydia',
age: 21,
};
const changeAge = (x = { ...person }) => (x.age += 1);
const changeAgeAndName = (x = { ...person }) => {
x.age += 1;
x.name = 'Sarah';
};
changeAge(person);
changeAgeAndName();
console.log(person);116. What's the output?
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Javob variantlari:
Anonymous Quiz
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A: {name: "Sarah", age: 22}
0%
B: {name: "Sarah", age: 23}
0%
C: {name: "Lydia", age: 22}
0%
D: {name: "Lydia", age: 23}
117. Which of the following options will return 6?
function sumValues(x, y, z) {
return x + y + z;
}117. Which of the following options will return 6?
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Javob variantlari:
Anonymous Quiz
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A: sumValues([...1, 2, 3])
0%
B: sumValues([...[1, 2, 3]])
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C: sumValues(...[1, 2, 3])
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D: sumValues([1, 2, 3])
118. What's the output?
let num = 1;
const list = ['🥳', '🤠', '🥰', '🤪'];
console.log(list[(num += 1)]);
118. What's the output?
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Javob variantlari:
Anonymous Quiz
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A: 🤠
0%
B: 🥰
0%
C: SyntaxError
0%
D: ReferenceError
119. What's the output?
const person = {
firstName: 'Lydia',
lastName: 'Hallie',
pet: {
name: 'Mara',
breed: 'Dutch Tulip Hound',
},
getFullName() {
return `${this.firstName} ${this.lastName}`;
},
};
console.log(person.pet?.name);
console.log(person.pet?.family?.name);
console.log(person.getFullName?.());
console.log(member.getLastName?.());119. What's the output?
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Javob variantlari:
Anonymous Quiz
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A: undefined undefined undefined undefined
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B: Mara undefined Lydia Hallie ReferenceError
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C: Mara null Lydia Hallie null
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D: null ReferenceError null ReferenceError
120. What's the output?
const groceries = ['banana', 'apple', 'peanuts'];
if (groceries.indexOf('banana')) {
console.log('We have to buy bananas!');
} else {
console.log(`We don't have to buy bananas!`);
}
120. What's the output?
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Javob variantlari
Anonymous Quiz
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A: We have to buy bananas!
0%
B: We don't have to buy bananas
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C: undefined
0%
D: 1
121. What's the output?
const config = {
languages: [],
set language(lang) {
return this.languages.push(lang);
},
};
console.log(config.language);121. What's the output?
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Javob variantlari:
Anonymous Quiz
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A: function language(lang) { this.languages.push(lang }
0%
B: 0
0%
C: []
0%
D: undefined
122. What's the output?
const name = 'Lydia Hallie';
console.log(!typeof name === 'object');
console.log(!typeof name === 'string');
122. What's the output?
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Anonymous Quiz
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A: false true
0%
B: true false
0%
C: false false
0%
D: true true
123. What's the output?
const add = x => y => z => {
console.log(x, y, z);
return x + y + z;
};
add(4)(5)(6);123. What's the output?
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Javob variantlari:
Anonymous Quiz
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A: 4 5 6
0%
B: 6 5 4
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C: 4 function function
0%
D: undefined undefined 6