typescript 50 lines · 9 steps

Parsing human names into structured parts

A name splitter that handles suffixes, prefixes, and 'Last, First' ordering before carving out first/middle/last.

Explained by highlit
Intermediate parsing string-manipulation normalization edge-cases tokenization
1interface ParsedName {
2 first: string;
3 middle: string;
4 last: string;
5 suffix: string;
6}
7 
8const SUFFIXES = new Set([
9 "jr", "sr", "ii", "iii", "iv", "v", "phd", "md", "esq",
10]);
11 
12const PREFIXES = new Set([
13 "mr", "mrs", "ms", "miss", "dr", "prof", "rev", "sir",
14]);
15 
16const normalizeSuffix = (token: string): string =>
17 token.replace(/\./g, "").toLowerCase();
18 
19export function splitName(fullName: string): ParsedName {
20 const empty: ParsedName = { first: "", middle: "", last: "", suffix: "" };
21 
22 if (fullName.includes(",")) {
23 const [lastPart, ...rest] = fullName.split(",");
24 fullName = `${rest.join(" ")} ${lastPart}`;
25 }
26 
27 const tokens = fullName.trim().split(/\s+/).filter(Boolean);
28 if (tokens.length === 0) return empty;
29 
30 let suffix = "";
31 const tail = tokens[tokens.length - 1];
32 if (tokens.length > 1 && SUFFIXES.has(normalizeSuffix(tail))) {
33 suffix = tokens.pop()!;
34 }
35 
36 if (tokens.length > 1 && PREFIXES.has(normalizeSuffix(tokens[0]))) {
37 tokens.shift();
38 }
39 
40 if (tokens.length === 0) return { ...empty, suffix };
41 if (tokens.length === 1) {
42 return { first: tokens[0], middle: "", last: "", suffix };
43 }
44 
45 const first = tokens.shift()!;
46 const last = tokens.pop()!;
47 const middle = tokens.join(" ");
48 
49 return { first, middle, last, suffix };
50}
01 / 01
STEP 01

Walkthrough

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Three takeaways
  1. 1Normalizing tokens against known sets lets you detect suffixes and titles regardless of punctuation or casing.
  2. 2Peeling recognized pieces off the ends first leaves a clean core to split into first/middle/last.
  3. 3Guarding each length boundary prevents the parser from crashing on empty or single-token input.

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