Soundex
// Minimum length of Soundex keys.var minLength = 4
// Soundex values belonging to characters.// This map also includes vowels (with a value of 0) to easily distinguish// between an unknown value or a vowel.var map = {}
map.a = map.e = map.i = map.o = map.u = map.y = 0
map.b = map.f = map.p = map.v = 1
map.c = map.g = map.j = map.k = map.q = map.s = map.x = map.z = 2
map.d = map.t = 3
map.l = 4
map.m = map.n = 5
map.r = 6
/*** Get the soundex key from a given value.** @param {string} value* @param {number} [maxLength=4]* @returns {string}*/function soundex(value, maxLength) {
var lowercase = String(value).toLowerCase()
/** @type {Array.<string|number>} */var results = []
var index = -1
/** @type {string} */var character/** @type {number} */var previous/** @type {number} */var phoneticswhile (++index < lowercase.length) {
character = lowercase.charAt(index)
phonetics = map[character]
if (index === 0) {
// Initial letterresults.push(character.toUpperCase())
} else if (phonetics && phonetics !== previous) {
// Phonetics valueresults.push(phonetics)
} else if (phonetics === 0) {
// Vowelphonetics = null
} else {
// Unknown character (including H and W)phonetics = previous}previous = phonetics}return pad(results.join('')).slice(0, maxLength || minLength)
}/*** Pad a given value with zero characters. The function only pads four characters.** @param {string} value* @returns {string}*/function pad(value) {
var length = minLength - value.length
var index = -1
while (++index < length) {
value += '0'
}return value}console.log(
soundex('Joe'),
soundex('Smith'),
soundex('Ed'),
soundex('Vilowat')
)
Was talking with someone about Soundex… I grabbed this implementation from the soundex-code npm package from Titus Wormer…
Soundex has always been super interesting to me for some reason.