Question

How might this be improved, as it pertains to the loop and the regex replace?

var properties = { ... };
var template = element.innerHTML;

for (var name in properties) {
    template = template.replace
        (new RegExp('\\${' + name + '}', 'gm'), properties[name]);
}

element.innerHTML = template;

Is there a way I could get all the matches for /\$\{\w+\}/gm and just use those to build a new string once for the entire operation?

Answer 1

I agree with Jason and Hans WRT not bothering with this from a performance perspective.

But, i would have written it differently in the first place:

element.innerHTML
  = template.replace(/[$][{](\w+)[}]/g, function(x,y){return properties[y]||x;})

Some things to keep in mind

1. If at all possible, you want to avoid looping over the creation of a RegExp for each iteration. Compiling them is generally considered costly. Or even generalize that to any object creation. Though not at the cost of readability/maintainability.
2. If you’re creating RegExp dynamically, be sure the result is a RegExp, otherwise see #1 as you’ll likely be able to apply it.