正则表达式和Openrefine中的值匹配

Question

I am trying to use the value.match command in OpenRefine 2.6 for splitting two columns based on a 4 number date.

A sample of the text is:

"first sentence, second sentence, third sentences, 2009"

What I do is going to "Add column based on this column" and insert

value.match(\\d{4})

but I get the error

Parsing error at offset 12: Missing number, string, identifier, regex, or parenthesized expression

any idea of the possible solution?

Answer 1

You need to fix 3 things to get this working:

1) As Wiktor says you need to start & end the regular expression with a forward slash /

2) The 'match' function requires you to match the whole string in the cell, not just the fragment you need - so your regular expression needs to match the whole string

3) To extract part of a string with 'match' you need to have capture groups in your regular expression- that is use ( ) around the bit of the regular expression you want to extract. The captured values will be put in an array and you will need to get the string out of tge array to store it in a cell

So you'll need something like:

value.match(/.*(\d{4})/)[0]

To get the four digit year from the end of the string