Question

Given strings

s1 = "abcfoodefbarghi" 

and

s2 = "abcbardefooghi"

How can I split s1 into “abc” and “defbarghi”
and s2 into “abc” and “defooghi”
That is: split a string into two on the first occurrence of either one of strings “foo” or “bar”

I suppose this could be done with s.split(/regexp/), but what should this regexp be?

Answer 1

Use a Regular Expression in this way:

var match = s1.match(/^([\S\s]*?)(?:foo|bar)([\S\s]*)$/);
/* If foo or bar is found:
  match[1] contains the first part
  match[2] contains the second part */

Explanation of the RE:

• [\S\s]*? matches just enough characters to match the next part of the RE, which is
• (foo|bar) either “foo”, or “bar”
• [\S\s]* matches the remaining characters

Parentheses around a part of a RE creates a group, so that the grouped match can be referred, while (?:) creates a non-referrable group.