puzzle 09 · javascript

What does this log?

console.log(["1", "7", "11"].map(parseInt));
[1, 7, 11]
[1, NaN, 3]
[1, 7, 3]
[NaN, NaN, NaN]

why

map passes (value, index) and parseInt takes (string, radix). So you get parseInt("1", 0)=1, parseInt("7", 1)=NaN (radix 1 is invalid), and parseInt("11", 2)=3 (binary). Use .map(Number) instead.

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