How do parseInt() and Number() behave differently when converting strings to numbers?
I found two links of performance compare among several ways of converting string to int.
string
int
parseInt(str,10) parseFloat(str) str << 0 +str str*1 str-0 Number(str)
http://jsben.ch/#/zGJHM
http://phrogz.net/js/string_to_number.html