如何将另一个变量添加到现有对象中？

Question

I have an object that I am passing through multiple pages and I want to add another variable into it and am not sure how to do that.

I have tried tried just equating the object to the variable I want to add but that just overwrites the object.

The Object

this.appDetails = {
        Maids: Details.Maids,                  
        length: Details.length,                
        cMats: Details.cMats,                   
        specialReq: Details.specialReq,          
        Address: Details.Address,                 
        Date: Details.Date,                      
        Payment: "By Credit/Debit Card",
        UID: this.id
      } 

The variable I want to add

var M = document.getElementById('Mobile').textContent;

Answer 1

this.appDetails = {
        Maids: Details.Maids,                  
        length: Details.length,                
        cMats: Details.cMats,                   
        specialReq: Details.specialReq,          
        Address: Details.Address,                 
        Date: Details.Date,                      
        Payment: "By Credit/Debit Card",
        UID: this.id
} 

addNewProperty(){
   this.appDetails.M = document.getElementById('Mobile').textContent;
   //or 
   this.appDetails["M"] = document.getElementById('Mobile').textContent;
}