Positive look behind in JavaScript regular expression

Question

I've a document from which I need to extract some data. Document contain strings like these

Text:"How secure is my information?" 

I need to extract text which is in double quotes after the literal Text:

How secure is my information? 

How do I do this with regex in Javascript

Answer 1

Lookbehind assertions were recently finalised for JavaScript and will be in the next publication of the ECMA-262 specification. They are supported in Chrome 66 (Opera 53), but no other major browsers at the time of writing (caniuse).

var str = 'Text:"How secure is my information?"',     reg = /(?<=Text:")[^"]+(?=")/;  str.match(reg)[0]; // -> How secure is my information? 

Older browsers do not support lookbehind in JavaScript regular expression. You have to use capturing parenthesis for expressions like this one instead:

var str = 'Text:"How secure is my information?"',     reg = /Text:"([^"]+)"/;  str.match(reg)[1]; // -> How secure is my information? 

This will not cover all the lookbehind assertion use cases, however.