How to use a variable name in a regex?

[Yansky]

Hi, if I have a string assigned to a variable, how can I use that
variable in a regex?

e.g. I would like to do something like this:
var words = 'the quick brown browning fox';
var key = getKey();
var patt=/\bkey\b/;
patt.test(words);

Unfortunately I can't just put the string I'm searching for directly
in the regex, because it will be changing each time this bit of the
script is run.

Any help would be appreciated.
Cheers.

 

[Martin Honnen]

Hi, if I have a string assigned to a variable, how can I use that
variable in a regex?

e.g. I would like to do something like this:
var words = 'the quick brown browning fox';
var key = getKey();
var patt=/\bkey\b/;

Don't use a regular expression literal then, instead use the new RegExp
constructor
var patt = new RegExp("\\b" + key + "\\b");

 

[Yansky]

Don't use a regular expression literal then, instead use the new RegExp
constructor
   var patt = new RegExp("\\b" + key + "\\b");

Thanks, I had tried new RegExp earlier but I forgot to escape the
backslashes.
Cheers.