Positive look behind in JavaScript regular expression

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

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.

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.

I just want to add something: JavaScript doesn't support lookbehinds like (?<= ) or (?<! ).

But it does support lookaheads like (?= ) or (?! ).

You can just do:

/Text:"(.*?)"/

Explanation:

• Text:" : To be matched literally
• .*? : To match anything in non-greedy way
• () : To capture the match
• " : To match a literal "
• / / : delimiters

string.match(/Text:"([^"]*)"/g)

<script type="text/javascript">
var str = 'Text:"How secure is my information?"';
var obj = eval('({'+str+'})')
console.log(obj.Text);
</script>