Gists showing the difference of using the nullability resources from Kotlin

Personal.kt

class PersonalInfo(val phone: String?)

class Person(val personalInfo: PersonalInfo?)

PhoneGetter.java

class PhoneGetter {
  
  public String getPhone(Person person) {
     if (person == null) return ""

     val personalInfo = person.personalInfo
     if (personalInfo == null) return ""

     val phone = personalInfo.phone
     if (phone == null) return ""

     return phone
  }
}

PhoneGetter.kt

fun getPhone(person: Person?): String {
   return person?.personalInfo?.phone ?: ""
}