Winning at Guess Who in Just a Few Steps

For the fun of it, I created an interactive decision tree for playing the game of Guess Who?.

Try it out and let me know if you come up with better features that create a smaller decision tree.

Originally I had more features, but removed them because I decided that if I had to explain to my 7 year old what I meant, it probably wasn’t a fair question.

Easy Date parsing with JavaScript

Date.fromString()

For the impatient, scroll to the bottom of the page for an interactive example.

Date.fromString() is a method that allows you to easily parse user input into a date. There are currently many implementations of calendar pop-ups that aim to solve a similar problem. However, these calendars are cumbersome to use if the target date is more than a couple months away. The goal of this project is to parse free-form user input into a valid Date object.

Date.fromString() accepts two parameters:

• input
  string — User input string to parse
• options optional
  object — An object that can override the default behavior
  { order: 'MDY', strict: false }

Examples

console.log(Date.fromString('Sept 5th, 2006  4:00 pm'));
// Tue Sep 05 2006 16:00:00 GMT-0600 (MDT)
 
console.log(Date.fromString('Sept 5th, 2006  4:23pm'));
// Tue Sep 05 2006 16:23:00 GMT-0600 (MDT)
 
console.log(Date.fromString('Sept 5th, 2006  4pm'));
// Tue Sep 05 2006 16:00:00 GMT-0600 (MDT)
 
console.log(Date.fromString('Sept 5th, 2006  12:34:56 am'));
// Tue Sep 05 2006 00:34:56 GMT-0600 (MDT)
 
console.log(Date.fromString('Sept 5th, 2006  7:30 am'));
// Tue Sep 05 2006 07:30:00 GMT-0600 (MDT)
 
console.log(Date.fromString('2006/09/05  4:23pm'));
// Tue Sep 05 2006 16:23:00 GMT-0600 (MDT)
 
console.log(Date.fromString('2006/09/05'));
// Tue Sep 05 2006 00:00:00 GMT-0600 (MDT)
 
console.log(Date.fromString('9/5/06'));
//Tue Sep 05 2006 00:00:00 GMT-0600 (MDT)
 
console.log(Date.fromString('2/13/78'));
// Mon Feb 13 1978 00:00:00 GMT-0700 (MST)
 
console.log(Date.fromString('Feb 13 09'));
// Fri Feb 13 2009 00:00:00 GMT-0700 (MST)

When part of the date is left off, it fills in the missing parts with today’s details. When these examples were written, it was November 25, 2008.

console.log(Date.fromString('Feb 13th'));
// Wed Feb 13 2008 00:00:00 GMT-0700 (MST)
 
console.log(Date.fromString('2/13'));
// Wed Feb 13 2008 00:00:00 GMT-0700 (MST)
 
console.log(Date.fromString('4pm'))
// Tue Nov 25 2008 16:00:00 GMT-0700 (MST)

If you would rather have the date not fill in those parts, pass the option strict set to true.

console.log(Date.fromString('4pm'))
// Tue Nov 25 2008 16:00:00 GMT-0700 (MST)
 
console.log(Date.fromString('4pm', {strict:true}))
// Invalid Date

Sometimes the date cannot be parsed without ambiguity. In these cases, the default ordering of month/day/year (MDY) is used. To change this behavior, pass the option order set to your preferred ordering; YMD, DMY, etc.

console.log(Date.fromString('09/05/06'));
// Tue Sep 05 2006 00:00:00 GMT-0600 (MDT)
 
console.log(Date.fromString('09/05/06', {order: 'YMD'}));
// Wed May 06 2009 00:00:00 GMT-0600 (MDT)
 
console.log(Date.fromString('09/05/06', {order: 'DMY'}));
// Tue May 09 2006 00:00:00 GMT-0600 (MDT)

Finally, try it for yourself. I have not been able to test this much in browsers other than Firefox on Linux, so if you find any bugs, please let me know.

Output:

The project is hosted at BitBucket and can be found at http://bitbucket.org/mazzarelli/js-date/downloads/.

You can download the source http://bitbucket.org/mazzarelli/js-date/downloads/date.js
or the minified version at http://bitbucket.org/mazzarelli/js-date/downloads/date.min.js.