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

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

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