使用javascript和regex解析问题的日期

Question

So I've been trying to get a jsfiddle example with d3.js working where it say takes in a string input such as;

"8/8/2011 12:00:00 AM"

And with that string can create a Date Object from parsing out the date info with regex.

I've been using near identical regex from this one. The format I'm trying to capture is a simple MM/DD/YYYY with actual validation I'll do by passing it into a Date object later on.

The actual regex pattern I came up with to do small validation is:

(([01]?[0-2]|[0-9])(\/)([0-2]?[0-9]|3[01])(\/)((19|20)\d{2}))

However my pattern is giving me some issues it seems with flags and matching/validating. Rubular validates fine without any flags and gets all the dates matched, but will break if I put the global flag (g) on the pattern. However with regex101 I need to put the global flag (g) for it to be able to match all the dates I put for test strings. I'm confused if the flag truly matters or not and would love some clarification.

Next to my jsfiddle example which stopped giving me any alert or feedback. However I'm also having trouble getting RegEx.exec(str) to properly work like I want. I thought I had it pushing the first entry in the array, which would be the date string I wanted. However like I said I don't get any feedback or alerts pop-up that I have set. According to jsfiddle my javascript is valid, so I'm at a lost.

I have it all commented with the logic of what I was trying to do, but I've tried everything that I could think of and wouldn't mind someone else taking a small look and pointing out something I may have missed.

Answer 1

I know this isn't using regex at all, but have you tried using the Date.parse() function in javascript? In your case, you can do something like this:

var dateString = "8/10/2011 12:00:00 AM"; // used different month to date for highlighting purposes
var date = new Date();
date.setTime(Date.parse(dateString));

date.getFullYear(); // returns 2011;
date.getMonth() // returns 7 (months are 0-11)
date.getDate(); // returns 10

More info here: MDN Date.parse()