# 获取生日
```
function getBirthdayFromIdCard(idCard) {
var birthday = "";
if(idCard != null && idCard != ""){
if(idCard.length == 15){
birthday = "19"+idCard.substr(6,6);
} else if(idCard.length == 18){
birthday = idCard.substr(6,8);
}
birthday = birthday.replace(/(.{4})(.{2})/,"$1-$2-");
}
return birthday;
}
```
