Compare ISO 8601 date strings in javascript

Question

I want to compare ISO 8601 dates in javascript as strings instead of making Date objects for each string and comparing objects.

var date_array = ['2012-10-01','2012-11-27','2012-12-23'];
console.log(date_array[0] < date_array[1])  // gives true
console.log(date_array[1] > date_array[2])  // gives false

My reason for doing this is I believe string comparisons should be faster than making objects for each date string and comparing objects.

These comparisons seem to work as expected in some browsers. Can I expect this sort of alphabetical string comparison to work in all browsers? 排列的 字符串比较适用于所有浏览器吗？ Is this method of date comparison actually faster than using Date objects?

Answer 1

Using that comparison operator will look at the strings values lexicographically , which means the dictionary order .

In ASCII, the decimal digits are sequentially stored smallest ( 0 , 0x30 ) to largest ( 9 , 0x39 ). If they're consistently in this format, largest value (year) to smallest (day) and always 0 padded to the largest possible value, then these comparisons will be fine.