Regular expressions that retain two decimal places

A percent regular expression that retains up to two decimal places: /^\d+\.? \d{0,2}%$/

44.5% 44.66% 0.3% 5% All right 33.444%-5.66% are wrong

A percent regular expression that has and retains only two decimal places: /^\d+\.? \d{2}%$/

44.66% correct 0.3% 5% 33.444% -5.66% all wrong

Js:/^\d+\.? \d{0,2}%$/
Java: ^\\d+\\.? \\d{0,2}%$

function Ispercent () {
var str = "0.47%";
alert (str);
if (str.length!=0) {
Alert (1);
var reg = /^\d+\.? \d{2}%$/;
var r = Str.match (reg);
Alert (R);
if (r==null)
Alert (' Sorry, you have entered an incorrect percentage format! '); Please change "date" to the name of the property you need to verify!
}
}

Regular expressions that retain two decimal places