I try to make a string out of an object.

    foo ():string
    {
      let obj = {name:"sam", age:"50"};   // my object

      let str="";
      Object.keys (obj).forEach ((k) => str += "key: " + k + " = val: " + obj [k] + ",    ");
      if (str.length > 0)
      {
        str = str.substr (0, str.length - 2);
      }
     
      return str;       // string: "key: name = val: sam,   key: age = val: 50" 
    }

Works as expected.
Is there another way to do that better? Is there a sort of toString and join for plain objects?