function commafy(obj) {
var num = obj.value;
if (isNaN(num)) {
alert('非法輸入');
num = '';
return;
}
//1.先去除空格,判斷是否空值和非數
num = num + "";
num = num.replace(/[ ]/g, "");
if (num == "") {
//alert("空值,結束");
return;
}
if (isNaN(num)) {
//alert("非數,結束");
return;
}
//2.針對是否有小數點,分情況處理
var index = num.indexOf(".");
if (index == -1) {//無小數點
var reg = /(-?\d+)(\d{3})/;
while (reg.test(num)) {
num = num.replace(reg, "$1,$2");
}
} else {
var intPart = num.substring(0, index);
var pointPart = num.substring(index + 1, num.length);
var reg = /(-?\d+)(\d{3})/;
while (reg.test(intPart)) {
intPart = intPart.replace(reg, "$1,$2");
}
num = intPart + "." + pointPart;
}
obj.value = num;
}
//轉回數字
function onComm(obj) {
var num = obj.value;
num = num + "";
num = num.replace(/[,]/g, "");
obj.value = num;
}