How to get only some of the elements of an object using only for-in and if-else

Question

For example, if we have the following object in javascript:

var person,
    property;
    
    person = {
        firstName: "John",
        lastName:"Doe",
        age: 50,
        eyeColor: "blue",
        hairColor: "black",
        profession: "doctor"
    }

How do I print out only the second and fourth property of this object with for-in and if-else?

Answer 1

another way would be.

var person = {
    firstName: "John",
    lastName: "Doe",
    age: 50,
    eyeColor: "blue",
    hairColor: "black",
    profession: "doctor"
  }
  
  for(key in person){
    var index = Object.keys(person).indexOf(key);
    if(index === 1 || index === 3){
      console.log("Key:", key, ", Value:", person[key]);
    }
  }