What is the purpose of isFinite function?
Interviewer Expectations for this Question
01
Core Competency
Assesses fundamental understanding of JavaScript conventions, runtime behavior, and memory/performance considerations.
02
Evaluation Criteria
Hiring managers look for precision, avoidance of ambiguous jargon, and ability to explain trade-offs under real production conditions.
Comprehensive Model Answer
Verified Solution
The isFinite() function is used to determine whether a number is a finite, legal number. It returns false if the value is +infinity, -infinity, or NaN (Not-a-Number), otherwise it returns true.
isFinite(Infinity); // false
isFinite(NaN); // false
isFinite(-Infinity); // false
isFinite(100); // true
Candidate Response Strategy & Interview Tips
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