Gautam Makavana

Essential Front-End Interview Topics Explained #day 7

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Gautam Makavana
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Essential Front-End Interview Topics Explained #day 7

  1. Question: What will be the output of console.log(5 - "2")?

    Answer: The output will be 3. JavaScript will perform the subtraction operation, converting the string "2" to a number.

  2. Question: Given the variable bool = true, what will be the output of console.log(typeof bool)?

    Answer: The output will be "boolean". The typeof operator will return the data type of the variable, which is boolean in this case.

  3. Question: What will be the output of console.log(null)?

    Answer: The output will be null.

  4. Question: What will be the output of console.log(typeof [1, 2, 3]?

    Answer: The output will be "object". In JavaScript, arrays are considered objects.

  5. Question: Given the object person = { name: "Alice", age: 30 }, what will be the output of console.log(person)?

    Answer: The output will be an object representation of person: { name: 'Alice', age: 30 }.

  6. Question: What will be the output of console.log(undefined)?

    Answer: The output will be undefined.

  7. Question: If you have three variables x = 5, y = "2", and z = "3", what will be the output of console.log(x + y + z)?

    Answer: The output will be "523". JavaScript will perform string concatenation.

  8. Question: What will be the output of console.log(true + true)?

    Answer: The output will be 2. In JavaScript, true is treated as 1 in numeric operations.

  9. Question: Given the variable arr = [1, 2, 3], what will be the output of console.log(arr)?

    Answer: The output will be the array representation of arr: [1, 2, 3].

  10. Question: What will be the output of console.log(typeof "hello")?

    Answer: The output will be "string".

  11. Question: What will be the output of console.log(5 - "2")?

    Answer: The output will be 3. JavaScript will perform the subtraction operation, converting the string "2" to a number.

  12. Question: Given the variable bool = true, what will be the output of console.log(typeof bool)?

    Answer: The output will be "boolean". The typeof operator will return the data type of the variable, which is boolean in this case.

  13. Question: What will be the output of console.log("2" * "3")?

    Answer: The output will be 6. JavaScript will perform the multiplication operation, converting both strings "2" and "3" to numbers.

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