String ends with substring

Checks if a given string ends with a substring of another string.

• Use a for...in loop and String.prototype.slice() to get each substring of the given word, starting at the end.
• Use String.prototype.endsWith() to check the current substring against the text.
• Return the matching substring, if found. Otherwise, return undefined.

const endsWithSubstring = (text, word) => {
  for (let i in word) {
    const substr = word.slice(0, i + 1);
    if (text.endsWith(substr)) return substr;
  }
  return undefined;
};

endsWithSubstring('Lorem ipsum dolor sit amet<br /', '<br />'); // '<br /'