用Javascript解析时间字符串

Question

So, I have this web server that parses an XML-file with a certain 'time-period'.

The time-period is presented as follows (I can't change this):

00:05:00 00:09:15 01:13:15 in an HH:MM:SS format.

I want to do an _.filter() select on all objects with a date between for instance 00:00:00 and 00:10:00 , and then a filter with all objects between 00:10:00 and 00:20:00 .

EDIT (clarification): With the time periods are 'times watched'. Let's say there are 50 entries of the time period, ranging from 00:00:00 to 1:30:00, but I want to make a new list that contains

• The time period
• The average 'times watched' in that time period.

This means I need some way to say: 'Select all time periods between zero minutes and 10 minutes. Give me a list of those. Compute the mean'.

For that, I would need to have some possibility to do arithmetic operations, seeing I would like to

• Compare dates
• Add 10 minutes on each iteration

However, the Javascript Date object doesn't seem to handle 'just times' that well, neither does the moment.js library. How would I go for this?

Answer 1

Here is how I would do in JS:

times=['00:05:00', '00:09:15', '01:13:15'];

1. First get seconds

    function getsec(time){ arr=time.split(':'); return (+arr[0])*3600 + (+arr[1])*60 + (+arr[2]); } times.map(getsec) [ 300, 555, 4395 ] 

2. Then filter times into slots of particular time period

    function filter(last, curr, index, array){ chk=parseInt(curr/600); //slots for 10 minutes if (typeof last[chk] === 'undefined') { last[chk]=[]; last[chk].push(curr); } else last[chk].push(curr); return(last) } times.map(getsec).reduce(filter,[]); [ [ 300, 555 ], , , , , , , [ 4395 ] ] 

   Returns array of arrays. Each child array contains times within slots in increasing order

3. Calculate mean

    function avg(last, curr, index, array){ if(index==array.length-1) return (last+curr)/array.length; else return last+curr; } times.map(getsec).reduce(avg,0); 1750 function getavg(arr){ return arr.reduce(avg,0); } times.map(getsec).reduce(filter,[]).map(getavg); [ 427.5, , , , , , , 4395 ] 

   Since we are dealing with array of arrays we need a wrapper.

Finally I would say that if you have many entries, databases would be faster.

Answer 2

Simplest way would be for you to convert everything into seconds, and then do your thing.

inSeconds = function(time) {
  var secs, arr = [];
  arr = time.split(':').map(function(item) { return parseInt(item) });
  secs = arr[0]*3600 + arr[1]*60 + arr[2];
  return secs;
}