Not really good in regular expression, but why when a match is found console.log fires two times?

$('#name').keyup(function() {
    var regex = /[\€]/g;
    var count = (m = $(this).val().match(regex)) ? m.length : 0; // Num matches
    console.log(count);
});

Output with 'hello':

0
0
0
0
0

After adding '€' symbol to 'hello' we have:

0
0
0
0
0
1
1

After adding 'h' symbol to 'hello€' we have:

0
0
0
0
0
1
1
1

Shouldn't be just one 1 after adding '€' to 'hello'?