Extracts substrings from the given `string` by using `regexp`.

extract.js

/**
 * Extracts substrings from the given `string` by using `regexp`.
 * @type {{
 *   (regexp: RegExp, string: string) => RegExpExecArray;
 *   <T>(regexp: RegExp, string: string, handler: (matches: RegExpExecArray) => T) => T;
 * }}
 */
const extract = (regexp, string, handler) => {
  const matches = regexp.exec(string) ?? [];
  return handler ? handler(matches) : matches;
};

extractGroups.js

/**
 * Extracts substrings from the given `string` by using `regexp`.
 * @type {{
 *   (regexp: RegExp, string: string) => Record<string,string>;
 *   <T>(regexp: RegExp, string: string, handler: (matches: RegExpExecArray) => T) => T;
 * }}
 */
const extractGroups = (regexp, string, handler) => {
  const matches = regexp.exec(string) ?? [];
  return !handler ? matches.groups ?? {} : handler(matches);
};

~example-extract-run.js

const sentences = [
  'Hi!',
  'Hello world!',
  'Hello crazy world.'
];
for (const sentence of sentences) {
  // Extracts the first and second word from the given string.
  const [first, second] = extract(
    /(\S+)\s+(\S+)/,
    sentence,
    ([match, first, second]) => [first, second]
  );
  console.log({first, second});
}

// Prints {first: undefined, second: undefined}
// Prints {first: "Hello", second: "world!"}
// Prints {first: "Hello", second: "crazy"}

~example-extractGroups-run.js

const sentences = [
  'Hi!',
  'Hello world!',
  'Hello crazy world.'
];
for (const sentence of sentences) {
  // Extracts the first and second word from the given string.
  const {first, second} = extractGroups(
    /(?<first>\S+)\s+(?<second>\S+)/,
    sentence
  );
  console.log({first, second});
}

// Prints {first: undefined, second: undefined}
// Prints {first: "Hello", second: "world!"}
// Prints {first: "Hello", second: "crazy"}