Question

We would like to split a string on instances of the pipe character |, but not if that character is preceded by an escape character, e.g. \|.

ex we would like to see the following string split into the following components

1|2|3\|4|5

1
2
3\|4
5

I’m expecting to be able to use the following javascript function, split, which takes a regular expression. What regex would I pass to split? We are cross platform and would like to support current and previous versions (1 version back) of IE, FF, and Chrome if possible.

Answer 1

Instead of a split, do a global match (the same way a lexical analyzer would):

• match anything other than \\ or |
• or match any escaped char

Something like this:

var str = "1|2|3\\|4|5";
var matches = str.match(/([^\\|]|\\.)+/g);

A quick explanation: ([^\\|]|\\.) matches either any character except '\' and '|' (pattern: [^\\|]) or (pattern: |) it matches any escaped character (pattern: \\.). The + after it tells it to match the previous once or more: the pattern ([^\\|]|\\.) will therefor be matches once or more. The g at the end of the regex literal tells the JavaScript regex engine to match the pattern globally instead of matching it just once.