Filter and Sort (least concise and enjoyable to write from the top, to the most concise and enjoyable at the bottom)

01_filter_sort.php

<?php
$fields  = array('firstName', 'middleName', 'lastName', 'suffix');
$names[] = array('firstName' => 'Diane ',     'middleName' => 'Tanya ', 'lastName' => ' Douglas', 'suffix' => '');
$names[] = array('firstName' => 'Jon ',       'middleName' => '',       'lastName' => ' Watson',  'suffix' => '');
$names[] = array('firstName' => ' Michelle ', 'middleName' => '',       'lastName' => ' Ajuria',  'suffix' => '');
$names[] = array('firstName' => 'Elliot ',    'middleName' => '',       'lastName' => 'Gray ',    'suffix' => 'II');
$names[] = array('firstName' => ' Jason ',    'middleName' => '',       'lastName' => 'Doran',    'suffix' => '');

// drop superfluous spaces and empty name parts (i.e. if there is no middle name, get rid of it)
$names = array_map(function($name) {
    return array_map(function($part){ return trim($part); }, $name);
}, $names);

// drop records with last names starting with 'W'
$names = array_filter($names, function($name) {
    return !preg_match('/^[w]/iu', $name['lastName']);
});

// sort descending by last name (names closer to Z first)
usort($names, function($a, $b){ return strcmp($b['lastName'], $a['lastName']); });

// build an array where each value corresponds to a person's full name (i.e. Diane Tanya Douglas)
$names = array_map(function($name) use($fields) {
    return array_reduce($fields, function($parts, $field) use($name) {
        if (!empty($name[$field])) $parts[] = $name[$field]; return $parts;
    }, array());
}, $names);

// print names one per line (use portable line break -- i.e. line break of the current OS)
foreach ($names as $name) { echo join(' ', $name), PHP_EOL; }

02_filter_sort.js

var fields = ['firstName', 'middleName', 'lastName', 'suffix'],
    names  = [
    {'firstName': 'Diane ',     'middleName': 'Tanya ', 'lastName': ' Douglas', 'suffix': ''   },
    {'firstName': 'Jon ',       'middleName': '',       'lastName': ' Watson',  'suffix': ''   },
    {'firstName': ' Michelle ', 'middleName': '',       'lastName': ' Ajuria',  'suffix': ''   },
    {'firstName': 'Elliot ',    'middleName': '',       'lastName': 'Gray ',    'suffix': 'II' },
    {'firstName': ' Jason ',    'middleName': '',       'lastName': 'Doran',    'suffix': ''   }];

// trim superfluous white-space
names.forEach(function(name){
  Object.keys(name).forEach(function(field){ name[field] = name[field].trim() })
})

// drop records with last names starting with 'W' and sort
names = names.filter(function(name){ return !/^w/i.test(name.lastName) })
             .sort(function(a, b){ return (a.lastName === b.lastName) ? 0 : (a.lastName > b.lastName) ? -1 : 1;})

// print full names one per line ignoring empty name parts (i.e. if middle name is empty, get rid of it)
names.forEach(function(name){
  name = fields.reduce(function(result, field){ name[field] && result.push(name[field]); return result; }, [])
  console.log(name.join(' '))
})

03_filter_sort.scala

import scala.collection.mutable.Map
val fields = List("firstName", "middleName", "lastName", "suffix")
var names  = List(
    Map("firstName"  -> "Diane"     , "middleName" -> "Tanya " , "lastName"   -> " Douglas", "suffix"   -> ""     ),
    Map("middleName" -> ""          , "firstName"  -> "Jon "   , "lastName"   -> " Watson" , "suffix"   -> ""     ),
    Map("firstName"  -> " Michelle ", "lastName"   -> " Ajuria", "middleName" -> ""        , "suffix"   -> ""     ),
    Map("firstName"  -> "Elliot "   , "suffix"     -> "III"    , "middleName" -> ""        , "lastName" -> "Gray "),
    Map("firstName"  -> " Jason "   , "middleName" -> ""       , "lastName"   -> "Doran"   , "suffix"   -> ""     ))

// trim superfluous spaces
names foreach { name => name foreach {case (key, value) => name(key) = value.trim() } }

// drop records where last name starts with 'W'
names = names filterNot { _("lastName").startsWith("W")}

// sort descending by last name
names = names sortWith  { (e1, e2) => (e1("lastName") compareTo e2("lastName")) < 0 } reverse

// print full names one per line ignoring empty name parts (i.e. if middle name is empty, get rid of it)
names foreach           { name =>
    var record:List[String] = Nil
    for(field <- fields reverse) if (name(field).length > 0) record = name(field) :: record
    println(record.mkString(" "))
}

04_filter_sort.rb

fields = [:firstName, :middleName, :lastName, :suffix]
names  = [
{firstName:  'Diane'     , middleName: 'Tanya ' , lastName:   ' Douglas', suffix:   ''     },
{middleName: ''          , firstName:  'Jon '   , lastName:   ' Watson' , suffix:   ''     },
{firstName:  ' Michelle ', lastName:   ' Ajuria', middleName: ''        , suffix:   ''     },
{firstName:  'Elliot '   , suffix:     'III'    , middleName: ''        , lastName: 'Gray '},
{firstName:  ' Jason '   , middleName: ''       , lastName:   'Doran'   , suffix:   ''     }]

# trim superfluous spaces
names.each     {|name| name.each {|key, val| name[key].strip!}}

# drop records where last name starts with 'W'
names.reject!  {|name| name[:lastName].match(/^w/i)}

# sort descending by last name
names.sort_by! {|name| name[:lastName]}.reverse!

# print full names one per line ignoring empty name parts (i.e. if middle name is empty, get rid of it)
names.each do |name|
  puts fields.inject([]) {|parts, field| parts << name[field] unless name[field].empty?; parts}.join ' '
end

Updated JavaScript example to remove the self-invoked function expression.

More observations

• "_" is an awesome language feature. Every language should have this.
• If JavaScript had a better standard library, it would be a beast of a language (it already is, so imagine if it had native startsWith, reject, sortBy).
• ES6 has startsWith so you can and should either shim it in or add it to a small string lib.

Even more

• I had forgotten that ES5 had .trim -- that puts JavaScript in a good place, very close to Ruby in my opinion.
• Even though Ruby wins slightly in LOC, that misses the point. The Ruby code is miles more readable than every other option, even fairly concise and idiomatic JavaScript.
• At the end of the day, PHP (even with 5.4 syntax), is no-where close to the expressiveness of JavaScript, let alone Ruby.

Rant on PHP for a minute

• While PHP actually has a respectable standard library, it is horrible regarding API consistency.
• Even with a vastly better standard library than JavaScript, PHP is still horrendous to read compared to pretty much everything else. I mean, I didn't even post the Python, CoffeeScript, and Groovy examples. I just felt like that would have crushed all life out of the PHP example.