Question

I have following code:

this.parse = function(whatToParse, currentItem) {
    var re = /\{j\s([a-z0-9\.\|_]+)\ss\}/gi;
    var newResult = whatToParse.replace(re, function(matches){
        alert(matches);
    });
}

whatToParse is:

            <h1>
                {j name s}
            </h1>
            <div>
                <nobr>{j description s}</nobr>
            </div>

But why matches is not array? It contains only matched string, without groups.
For example: alert(matches); alerts “{j name s}” and alert(matches[1]); alerts “j”.

Why? How to get first group?

P.S. I don’t understand it, because in PHP this RegExp works correctly.

Answer 1

See the documentation ^[MDN]. The captured values are passed as arguments to the function.

The arguments to the function are as follows:

Possible name   Supplied value
str             The matched substring. (Corresponds to $& above.)
p1, p2, ...     The nth parenthesized submatch string, provided the first argument to replace was a RegExp object. (Correspond to $1, $2, etc. above.)
offset          The offset of the matched substring within the total string being examined. (For example, if the total string was "abcd", and the matched substring was "bc", then this argument will be 1.)
s               The total string being examined.

(sorry for the formatting, but creating tables in Markdown is not easy)

So in your case:

var newResult = whatToParse.replace(re, function(match, firstGroup){
    alert(firstGroup);
});