Fuzzy search and replace multiple terms in a string.

search-and-replace-1.js

function replace(phrase, query) {
  return phrase.replace(            // SEARCH the phrase...
    RegExp('(' +                    // using a REGULAR EXPRESSION to capture...
    query                           // all matches in the QUERY.
      .trim()                       // Trim whitespace to PREVENT "EMPTY" WORDS when the query is...
      .split(/\s+/)                 // split into DISCREET SEARCHABLE "WORDS" (non-whitespace terms),...
      .sort(function(a,b) {         // SORTED by...
        return b.length - a.length; // descending length to PREVENT LOSS OF MATCHES previously replaced by shorter matches.
      }).map(function(word) {       // To capture non-word characters like PERIODS, HYPHENS, and APOSTROPHES,
        return word.split('')       // BETWEEN EACH CHARACTER of the word
          .join('\\W*');            // insert the regular expression for optional non-word characters.
      }).join('|')                  // Capture matches of ANY
    + ')', 'gi'),                   // and ALL of our terms (CASE-INSENSITIVE)...
    '<b>$1</b>');                   // and REPLACE them with BOLD text.
}

[
  'Don\'t you forget about me.',
  'Leave those kids alone',
  'Born in the U.S.A',
  'Bombs over Baghdad',
  'Us vs. them',
  'don\'t leave me',
  'u.s.a.! u.s.a.!'
].forEach(function(phrase) {
  console.log(replace(phrase, '  dont leave us '));
});

search-and-replace-2.js

var reWhitespace = /\s+/;

function replace(phrase, query) {
  var terms = query.trim().split(reWhitespace).sort(sortByLengthDescending).map(insertNonWordChars);
  var search = RegExp('(' + terms.join('|') + ')', 'gi');
  var replace = '<b>$1</b>';
  return phrase.replace(search, replace);
}

function sortByLengthDescending(a,b) {
  return b.length - a.length;
}

function insertNonWordChars(word) {
  return word.split('').join('\\W*');
}

[
  'Don\'t you forget about me.',
  'Leave those kids alone',
  'Born in the U.S.A',
  'Bombs over Baghdad',
  'Us vs. them',
  'don\'t leave me',
  'u.s.a.! u.s.a.!'
].forEach(function(phrase) {
  console.log(replace(phrase, '  dont leave us '));
});

search-and-replace-3.js

var reWhitespace = /\s+/;

function replaceAll(items, query) {

  var terms = query.trim().split(reWhitespace).sort(sortByLengthDescending).map(insertNonWordChars);
  var search = RegExp('(' + terms.join('|') + ')', 'gi');
  var replace = '<b>$1</b>';

  $.each(items, function(title, $el) {
    var match = title.replace(search, replace);

    if (match.length > title.length) {
      $el.text(match);
    }
    console.log($el.text());
  });
}

function sortByLengthDescending(a,b) {
  return b.length - a.length;
}

function insertNonWordChars(word) {
  return word.split('').join('\\W*');
}

var els = {
  'Don\'t you forget about me.':  $('<div>').text('Don\'t you forget about me.'),
  'Leave those kids alone':       $('<div>').text('Leave those kids alone'),
  'Born in the U.S.A':            $('<div>').text('Born in the U.S.A'),
  'Bombs over Baghdad':           $('<div>').text('Bombs over Baghdad'),
  'Us vs. them':                  $('<div>').text('Us vs. them'),
  'don\'t leave me':              $('<div>').text('don\'t leave me'),
  'u.s.a.! u.s.a.!':              $('<div>').text('u.s.a.! u.s.a.!')
};

replaceAll(els, '  dont leave us ');