How to understand isNaN

user_1914781 0
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I try below code block, the isNaN return true. The value is not NaN why the return value is true?

true 06-19 12:20:30.200


        var t = d3.timeParse("%Y-%m-%d %H:%M:%S.%L")("2022-06-19 12:20:30.200");
        v = d3.timeFormat("%m-%d %H:%M:%S.%L")(t)
        var isNan = isNaN(v)
        console.log(isNan,v)
<script src="https://unpkg.com/d3@7.0.4/dist/d3.min.js"></script>

d3.js
1 Answers

You should use Number.isNaN() instead. The global version of isNaN() has some confusing behavior.

When the argument to the isNaN function is not of type Number, the value is first coerced to a Number. The resulting value is then tested to determine whether it is NaN.

        var t = d3.timeParse("%Y-%m-%d %H:%M:%S.%L")("2022-06-19 12:20:30.200");
        v = d3.timeFormat("%m-%d %H:%M:%S.%L")(t)
        var isNan = Number.isNaN(v)
        console.log(isNan,v)
<script src="https://unpkg.com/d3@7.0.4/dist/d3.min.js"></script>

user_49709670
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