Question

I’m not able to get an array from the result of a regex match:

var txt = '[Eig2]=>100 [Eig1]=="test"';
var reg = '(\\[)((?:[a-z][a-z]+))(\\d+)(\\])';
var m = txt.match(new RegExp(reg, ["i"]));
if (m != null) {
    for (var i = 0; i < m.length; i++) {
        console.log(m[i]);
    }
} else {
    console.log("null");
}

What it returns:

[Eig2] 
[ 
Eig 
2 
]

What I want:

[Eig2]
[Eig1]

May I have to do it without “new RegExp”, but with “/([)((?:[a-z][a-z]+))(\d+)(])/g” it does not work…

Some ideas?

Regards

Answer 1

First, I would simplify the expression:

var re = /\[([a-z]{2,}\d+)\]/ig;

I’ve added the /i for case insensitive matching and /g modifier to match multiple occurrences. Then you call it like this:

> txt.match(re);
  ["[Eig2]", "[Eig1]"]

To extract the first memory capture:

var captures = [];

txt.replace(re, function($0, $1) {
    captures.push($1);
});

Granted, .replace() is being abused here

Then, evaluate captures:

> captures
  ["Eigh2", "Eigh1"]

Update

A somewhat friendlier way to build the array of memory captures:

var captures = [], match;

while ((match = re.exec(txt)) !== null) {
    captures.push(match[1]);
});