Сортировать массив по значению в алфавитном порядке php

Как следует из названия, я хочу отсортировать массив по значению в алфавитном порядке в php.

$arr = array(
    'k' => 'pig',
    'e' => 'dog'
)

Станет

$arr = array(
    'e' => 'dog',
    'k' => 'pig'
)

Есть идеи?

РЕДАКТИРОВАТЬ: Вот фактический массив, который я хочу отсортировать.

Array ( [0] => Newtown [1] => Montgomery [2] => Welshpool [6] => Llanfyllin [7] => Llansanffraid [8] => Llanymynech [9] => Oswestry [14] => Oswestry Town Service [15] => Aston Way [16] => College Road [17] => Shrewsbury [18] => Royal Shrewsbury Hospital [19] => Worthen [20] => Brockton [22] => Cefn Blodwell [23] => Treflach [24] => Trefonen [25] => Morda [26] => Marches School [28] => North Shropshire College [37] => Park Hall [38] => Gobowen [39] => St Martins [40] => Ifton Heath [42] => Guilsfield [43] => Four Crosses [45] => Pant [46] => Llynclys [49] => Oswestry Town Service Schools [51] => Woodside School [56] => Whittington [57] => Babbinswood [58] => Hindford [59] => Ellesmere [62] => Forden [63] => Kingswood Cock Hotel [65] => Coleg Powys [85] => Borfa Green [86] => Bryn Siriol [87] => Maesydre School [92] => Crew Green [93] => Ford [104] => Llanrhaeadr [106] => Meifod [114] => Llangynog [116] => Llangedwyn [119] => Porthywaen [132] => Llanfair Caereinion [133] => Pontrobet [136] => Dolanog [141] => Llansilin [144] => Abermule [145] => Llandyssil [146] => Carhowel [149] => Cefn Coch [150] => Tregynon [151] => Manafon [152] => Berriew [157] => Bettws Cedewain [158] => Newtown High School [160] => Newtown Coleg Powys [173] => Llanerfyl [174] => Machynlleth [175] => Talybont [176] => Aberystwyth [183] => Bala [184] => Llanrwst [185] => Llandudno [188] => Middletown [196] => Llanidloes [202] => Wrexham [203] => Rhayader )