JavaScriptでワイルドカードを使いこなす！初心者向け解説10選

function wildcardToRegex(wildcard) {
  // アスタリスク(*)を正規表現の「任意の文字列」に変換
  // クエスチョンマーク(?)を正規表現の「任意の1文字」に変換
  const regex = wildcard.replace(/\*/g, ".*").replace(/\?/g, ".");
  return new RegExp(`^${regex}$`);
}

const pattern = "te*t?";
const regex = wildcardToRegex(pattern);
console.log(regex.test("test")); // true
console.log(regex.test("teat")); // true
console.log(regex.test("texts")); // false

const wildcard = "ja*a?";
const regex = wildcardToRegex(wildcard);

const words = ["java", "javascript", "japan", "jazz"];
const matchedWords = words.filter(word => regex.test(word));
console.log(matchedWords); // ["java", "japan"]

const wildcard = "*.txt";
const regex = wildcardToRegex(wildcard);

// ファイル名のリスト
const filenames = ["file1.txt", "file2.csv", "file3.txt", "file4.doc"];
// ワイルドカードに一致するファイル名を抽出
const matchedFilenames = filenames.filter(filename => regex.test(filename));
console.log(matchedFilenames); // ["file1.txt", "file3.txt"]

const wildcard = "https://*.example.com/*";
const regex = wildcardToRegex(wildcard);

const urls = [
  "https://www.example.com/index.html",
  "https://blog.example.com/post1.html",
  "https://www.google.com/search?q=example",
  "https://sub.example.com/page.html"
];

const matchedUrls = urls.filter(url => regex.test(url));
console.log(matchedUrls); // ["https://www.example.com/index.html", "https://blog.example.com/post1.html", "https://sub.example.com/page.html"]

function escapeWildcard(wildcard) {
  return wildcard.replace(/([\*\?])/g, "\\$1");
}

const escapedWildcard = escapeWildcard("example?*.com");
console.log(escapedWildcard); // "example\?\*\.com"

function customWildcardToRegex(wildcard, wildcardChars) {
  const { anyChar, anyString } = wildcardChars;
  const escapedAnyChar = anyChar.replace(/([.*+?^=!:${}()|[\]/\\])/g, "\\$1");
  const escapedAnyString = anyString.replace(/([.*+?^=!:${}()|[\]/\\])/g, "\\$1");

  const regexStr = "^" + wildcard
    .replace(escapedAnyChar, ".")
    .replace(escapedAnyString, ".*") + "$";

  return new RegExp(regexStr);
}

const customWildcard = "example@%com";
const customRegex = customWildcardToRegex(customWildcard, { anyChar: "@", anyString: "%" });
console.log(customRegex.test("example.com")); // true

const fs = require("fs");
const path = require("path");

function getFilesByWildcard(dir, wildcard) {
  const regex = wildcardToRegex(wildcard);
  return fs.readdirSync(dir).filter(file => regex.test(path.basename(file)));
}

const fileList = getFilesByWildcard("./", "*.txt");
console.log(fileList); // ["file1.txt", "file2.txt", "file3.txt"]

const wildcard = "example.com/*";
const regex = wildcardToRegex(wildcard);

const inputValue = "example.com/test";
console.log(regex.test(inputValue)); // true

const router = new Map();

function route(url, handler) {
  router.set(wildcardToRegex(url), handler);
}

function handleRequest(req) {
  for (const [regex, handler] of router.entries()) {
    if (regex.test(req.url)) {
      handler(req);
      break;
    }
  }
}

route("/posts/*", req => {
  console.log("This is a post request.");
});

handleRequest({ url: "/posts/123" }); // "This is a post request."

const data = [
  { id: 1, name: "apple" },
  { id: 2, name: "banana" },
  { id: 3, name: "grape" },
  { id: 4, name: "orange" },
  { id: 5, name: "melon" },
];

function filterData(data, wildcard) {
  const regex = wildcardToRegex(wildcard);
  return data.filter(item => regex.test(item.name));
}

const filteredData = filterData(data, "*a*e");
console.log(filteredData);
// 出力: [ { id: 1, name: 'apple' }, { id: 3, name: 'grape' } ]