From the Mozilla Developer Network:
[1,4,9].map(Math.sqrt)
will yield:
[1,2,3]
Why then does this:
['1','2','3'].map(parseInt)
yield this:
[1, NaN, NaN]
I have tested in Firefox 3.0.1 and Chrome 0.3 and just as a disclaimer, I know this is not cross-browser functionality (no IE).
I found out that the following will accomplish the desired effect. However, it still doesn’t explain the errant behavior of parseInt.
['1','2','3'].map(function(i){return +i;}) // returns [1,2,3]