SO - regexp highlight
http://stackoverflow.com/q/8433057/1011582
by dzejkej
HTML
<span id="result"></span>
JavaScript
var newCityString = 'Findling finds a fine fish';
var value = 'fin'
// ---
var search = new RegExp(value, 'gi');
newCityString = newCityString.replace(search, function(match, i) {
return '<span class="hl" style="background-color:yellow">' + match + '</span>';
});
// ---
document.getElementById('result').innerHTML = newCityString;