regex - JavaScript: "Dynamic" back reference RegExp replacement -

i want make replacements this:

var txt = "some text containing $_variable1 , $_variable2 inside of well."; var rx = /(\$_[a-z]+)/g  var $_variable1 = "a cat"; var $_variable2 = "a hotdog";  var replaced_txt = txt.replace(rx, $1); 

i want replaced_txt equal "...containing cat , hotdog ins...", way achieve i've found far this:

var replaced_txt = txt.replace(rx, function($1){return eval($1)}); 

and have feeling not elegant solution, no?

preferably i'd avoid eval()

i'm grateful ideas on this!

/c

you can this:

var values = {   '$_variable1': 'a cat',   '$_variable2': 'a hotdog' }; var replaced_txt = txt.replace(rx, function(_, varname) {   return values[varname] ? values[varname] : '<unknown variable: ' + varname + '>'; });