Question

I am trying to write something that would look at tweets and pull up info about stocks being mentioned in the tweet. People use $ to reference stock symbols on twitter but I cant escape the $.

I also dont want to match any price mention or anything like that so basically match $AAPL and not $1500

I was thinking it would be something like this

\b\$[a-zA-Z].*\b

if there are multiple matches id like to loop through them somehow so something like

while ((tweet = reg.exec(sym_pat)) !== null) {
   //replace text with stock data.
}

This expression gives me an unexpected illegal token error

 var symbol_pat = new RegExp(\b\$[a-z]*);

Thanks for the help if you want to see the next issue I ran into
Javascript AJAX scope inside of $.each Scope

Answer 1

var symbol_pat = new RegExp('\\b\\$[a-z]+\\b','gi');
// or
var symbol_pat = /\b\$[a-z]+\b/gi;

Also, for some reason JS can not calculate the beginning of a word by \b, it just catches the one at the end.

EDIT: If you’re replacing the stock symbols you can use the basic replace method by a function and replace that data with predefined values:

var symbol_pat = /(^|\s)(\$[a-z]+\b)/gi;
var stocks = {AAPL:1,ETC:2}
var str = '$aapl ssd $a a$s$etc $etc';
console.log(str);
str = str.replace(symbol_pat, function() {
    var stk = arguments[2].substr(1).toUpperCase();
    // assuming you want to replace $etc as well as $ETC by using
    // the .toUpperCase() method
    if (!stocks[stk]) return arguments[0];
    return arguments[0].replace(arguments[2],stocks[stk]);
});
console.log(str);