get Nested Object value without using if conditions

getNestedValue.js

const obj = {
  a: {
    b: {
      d: 2
    },
    c: {
      e: 5
    }
  }
};

const func = (obj, props) =>
  props.reduce((acc, val) => (acc && acc[val]) ? acc[val] : undefined, obj);

Object.prototype.getNestedValue = function(props) {
  return props.reduce((acc, val) => (acc && acc[val]) ? acc[val] : undefined, this);
}

console.log(func(obj, ['a', 'b', 'd'])); // 2
console.log(obj.getNestedValue(['a', 'c', 'e'])); // 5
console.log(obj.getNestedValue(['a', 'f', 'e'])); // undefined