Finding the difference between two string in Javascript with regex [closed]

Answer 1

If you are only concerned with testing whether a given string contains two or more sequential dot '.' characters:

var string = '$1..00',
    regexp = /(\.\.+)/;

alert('Is this regular expression ' + regexp + ' found in this string ' + string + '?\n\n' + regexp.test(string) + '\n\n' + 'Match and captures: ' + regexp.exec(string));

If you need it to match the currency format:

var string = '$1..00',
    regexp = /\$\d*(\.\.+)(?:\d\d)+/;

alert('Is this regular expression ' + regexp + ' found in this string ' + string + '?\n\n' + regexp.test(string) + '\n\n' + 'Match and captures: ' + regexp.exec(string));

But I caution you that Regular Expressions aren't for comparing the differences between two strings; they are used for defining patterns to match against given strings.

So, while this may directly answer how to find the "multiple dots" pattern, it is useless for "finding the difference between two strings".

The StackOverflow tag wiki provides an excellent overview and basic reference for RegEx. See: https://stackoverflow.com/tags/regex/info