var
r = /^\d+(\.\d+)?$/;
// 或者
var r = new RegExp("^\\d+(\\.\\d+)?$");
r =
new
RegExp(
"^\\d+(\\.\\d+)?$"
);
<input type="text" value="" onkeyup="this.value=this.value.replace(/\\D/g,\'\')" onafterpaste="this.value=this.value.replace(/\\D/g,\'\')">
