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What does console.log(5 << 2) print? JavaScript Numbers, Strings and Regular Expressions
Block 7, Numbers, Strings and Regular Expressions, question 10 of the JavaScript sample
console.log(5 << 2)What does this print?
Show the answer and why each option is right or wrong
Answer, C. 20
- A. 7
- Confuses the shift operator with addition, adding the shift amount to the original number.
- B. 10
- Assumes each left shift multiplies by 2 regardless of the shift count, applying the doubling only once instead of the two times requested.
- C. 20
- Correct. Shifting left by 2 multiplies the value by four, since each position shifted doubles it.
- D. 25
- Assumes each left shift multiplies by 5, confusing the shift count with the value being shifted.
Shifting an integer left by n bit positions is equivalent to multiplying it by two to the power of n. Shifting 5 left by 2 multiplies it by four, giving 20.
The answer above is what the Node interpreter printed when the snippet was run, not what someone expected it to do.
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