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✍️ Content byMd. Rakibul Islam
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MCQ
Multiple Choice · 100 questions
1Easydata types⏱ 30s

What does typeof null return in JavaScript?

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2Easyhoisting⏱ 40s

What is the output of the following code?

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javascript
console.log(x);
var x = 5;
3Easydata types⏱ 30s

Which of the following is NOT a primitive data type in JavaScript?

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4Easyoperators⏱ 30s

What is the key difference between == and === in JavaScript?

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5Easyarrow functions⏱ 60s

What does the following code output?

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javascript
const obj = {
  name: 'Dev',
  greet: () => {
    console.log('Hello, ' + this.name);
  }
};
obj.greet();
6Easyarrays⏱ 20s

Which method adds one or more elements to the END of an array and returns the new length?

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7Easynumbers⏱ 30s

What is the output of: console.log(0.1 + 0.2 === 0.3)?

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8Easyscope⏱ 60s

What does the following code output?

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javascript
for (let i = 0; i < 3; i++) {
  setTimeout(() => console.log(i), 0);
}
9Easyarrays⏱ 30s

How do you correctly check if a variable is an Array?

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10Easystring methods⏱ 30s

What is the output of the following code?

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javascript
let str = 'hello';
str.toUpperCase();
console.log(str);
11Easyvariables⏱ 25s

Which keyword declares a variable that cannot be reassigned?

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12Easydata types⏱ 20s

What is the output of: console.log(typeof undefined);

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javascript
console.log(typeof undefined);
13Easytruthy/falsy⏱ 30s

Which of these values is considered falsy in JavaScript?

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14Easyvariables⏱ 30s

What is the difference between let and var in terms of scope?

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15Easyloops⏱ 25s

What does the following loop print?

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javascript
for (let i = 0; i < 3; i++) {
  console.log(i);
}
16Easyoperators⏱ 20s

Which operator is used to check strict inequality?

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17Easyfunctions⏱ 25s

What will `typeof function(){}` return?

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javascript
console.log(typeof function(){});
18Easysyntax basics⏱ 15s

How do you write a single-line comment in JavaScript?

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19Easyoperators⏱ 35s

What is the output of the following code?

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javascript
console.log('5' + 3);
console.log('5' - 3);
20Easyarrays⏱ 20s

Which array method removes the LAST element and returns it?

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Showing 1–20 of 100 questions

Javascript MCQ Interview Questions — All Levels | UyTech