How to check if a parent object exists to avoid undefined error

I am using the below function to decide if I have new value for a key in my json doc or not. If I do, I go and use the new value, otherwise I use the previously stored value. This works fine if it is a direct value I am referencing, but for example if i use

home_addr.address_line_2 =
updateValue(oldData.home_address.address_line_2,
data.home_address_line_2)

and oldData.home_address does not exists it complains that address_line_2 is undefined. So how can I handle this in a way without having to check if each parent object is created to avoid this error ?

const updateValue = (oldvalue, newvalue) => {
    if (typeof newvalue !== "undefined" && newvalue !== null) {
        console.log("new Value to trim : " + newvalue)

        if (typeof newvalue == "boolean") {
            return newvalue;  
        } else if(typeof value === 'number') {
            return newvalue; 
        }
        else {
            return newvalue.trim();
        }
     
    } else {
        if (typeof oldvalue !== "undefined" && oldvalue !== null){
        return oldvalue;
        } else {
            return null
        }
    }
};