Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.lang.javascript > #26675

Re: function to get frequencies of a char array

Show all headers | View raw

Thomas 'PointedEars' Lahn wrote:

> Christoph M. Becker wrote:
> 
>> Or maybe using Array.prototype.reduce:
>>
>>     var a = ['a', 'b', 'j','c', 'd', 'j', 'j', 'j'];
>>     a.reduce(function (prev, curr) {
>>         if (prev.hasOwnProperty(curr)) {
>>             prev[curr]++;
>>         } else {
>>             prev[curr] = 1;
>>         }
>>         return prev;
>>     }, {});
> 
> While this works – but I would use “Object.create(null)” instead of “{}” to 
> avoid name collisions –, 

Good point!

> I find a “for” or “for–in” statement more obvious 
> and compatible:

I had deliberately ignored compatibility with older environments (i.e.
not ES 5 compatible), but of course, that may be an issue.  And I have
to admit that I would find a for(-in) loop more obvious, too, but it
seems to me that is a matter of habit.

Anyhow, I mainly wanted to point out that current ECMAScript
implementations offer interesting tools for functional/applicative
programming which might be worth consideration -- especially for long
time ECMAScript programmers who might not be aware of these tools.

-- 
Christoph M. Becker

Back to comp.lang.javascript | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

function to get frequencies of a char array JRough <janis.rough@gmail.com> - 2015-01-22 14:43 -0800
  Re: function to get frequencies of a char array Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-01-22 23:09 +0000
    Re: function to get frequencies of a char array JRough <janis.rough@gmail.com> - 2015-01-22 15:22 -0800
  Re: function to get frequencies of a char array JRough <janis.rough@gmail.com> - 2015-01-22 15:23 -0800
  Re: function to get frequencies of a char array "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2015-01-23 00:36 +0100
    Re: function to get frequencies of a char array "Christoph M. Becker" <cmbecker69@arcor.de> - 2015-01-23 14:27 +0100
      Re: function to get frequencies of a char array Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2015-01-23 16:52 +0100
        Re: function to get frequencies of a char array Scott Sauyet <scott.sauyet@gmail.com> - 2015-01-23 09:03 -0800
        Re: function to get frequencies of a char array "Christoph M. Becker" <cmbecker69@arcor.de> - 2015-01-23 23:03 +0100
        Re: function to get frequencies of a char array Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-01-24 14:29 +0000
          Re: function to get frequencies of a char array Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2015-01-24 15:36 +0100
            Re: function to get frequencies of a char array "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2015-01-24 16:06 +0100
              Re: function to get frequencies of a char array "Christoph M. Becker" <cmbecker69@arcor.de> - 2015-01-24 18:05 +0100
                Re: function to get frequencies of a char array "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2015-01-26 10:21 +0100
                Re: function to get frequencies of a char array "Christoph M. Becker" <cmbecker69@arcor.de> - 2015-01-26 13:22 +0100
                Re: function to get frequencies of a char array "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2015-01-26 15:50 +0100
                Re: function to get frequencies of a char array "Christoph M. Becker" <cmbecker69@arcor.de> - 2015-01-26 20:48 +0100
                Re: function to get frequencies of a char array "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2015-01-26 23:08 +0100
                Re: function to get frequencies of a char array Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2015-01-27 01:05 +0100
                Re: function to get frequencies of a char array "Christoph M. Becker" <cmbecker69@arcor.de> - 2015-01-27 13:55 +0100
                Re: function to get frequencies of a char array Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2015-01-27 14:50 +0100
                Re: function to get frequencies of a char array "Christoph M. Becker" <cmbecker69@arcor.de> - 2015-01-27 19:35 +0100
                Re: function to get frequencies of a char array Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2015-01-27 22:15 +0100
                Re: function to get frequencies of a char array "Christoph M. Becker" <cmbecker69@arcor.de> - 2015-01-31 00:40 +0100
            Re: function to get frequencies of a char array Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-01-24 17:49 +0000
              Re: function to get frequencies of a char array "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2015-01-26 10:23 +0100
              Re: function to get frequencies of a char array Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2015-01-27 01:00 +0100
                Re: function to get frequencies of a char array Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-01-27 01:37 +0000
                Re: function to get frequencies of a char array Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2015-01-27 03:03 +0100
    Re: function to get frequencies of a char array "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2015-01-23 15:29 +0100
  Re: function to get frequencies of a char array Denis McMahon <denismfmcmahon@gmail.com> - 2015-01-23 02:16 +0000
    Re: function to get frequencies of a char array Denis McMahon <denismfmcmahon@gmail.com> - 2015-01-23 02:18 +0000
    Re: function to get frequencies of a char array "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2015-01-23 09:06 +0100
      Re: function to get frequencies of a char array Stefan Weiss <krewecherl@gmail.com> - 2015-01-23 09:53 +0100
        Re: function to get frequencies of a char array "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2015-01-23 13:37 +0100
          Re: function to get frequencies of a char array "Christoph M. Becker" <cmbecker69@arcor.de> - 2015-01-23 13:49 +0100
    Re: function to get frequencies of a char array "Christoph M. Becker" <cmbecker69@arcor.de> - 2015-01-23 13:31 +0100
    Re: function to get frequencies of a char array Denis McMahon <denismfmcmahon@gmail.com> - 2015-01-23 14:49 +0000
    Re: function to get frequencies of a char array Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2015-01-23 17:09 +0100

csiph-web