jquery extract number from string

// Html: <span id="foo">280ms</span>

var text = $('#foo').text();
var number = parseInt(text, 10);
alert(number);

// parseInt('ms120'.replace(/[^0-9\.]/g, ''), 10);var id_of_div = "div_id_12";
var id_number = parseInt(id_of_div.replace(/[^0-9.]/g, ""));
console.log(id_number);//12