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Answer
A closure keeps a reference to outer-scope variables even after that function has returned.
Write reverse so that the following cases hold.
reverse("hello")"olleh"reverse("FrontendPro")"orPdnletnorF"Reverse the string with split, reverse, and join:
function reverse(str) {
return str.split("").reverse().join("");
}
Output
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How to read complexity and pick the right data structure as input grows.
O(1) and O(log n) keep UI snappy; O(n²) falls over as lists get long.
O(1) < O(log n) < O(n) < O(n²)A closure keeps a reference to outer-scope variables even after that function has returned.
Correct!
typeof returns a string describing the operand’s type.
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What is a closure in JavaScript?
A closure keeps references to outer variables even after the outer function returns.
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