搜索对象的数组列表

Question

I have an array list in a class the array is called realtorList. From my main class I store objects with realtor data to the realtorList. My data that is stored to a text file and is read in the first line. This is the first element in the realtorList after I store the first line of data.

[Realtor{licenseNumber= AA1111111 , firstName=Anna, lastName=Astrid, phoneNumber=111-111-1111, commission=0.011}]

When I read the next line of data from the input file I need to see if the licenseNumber in bold already exists in the realtorList. I am having trouble figuring out how to go about doing this.

For example if the next realtor data license number is AA1111111 how do I check the realtorList for AA1111111 which does exist for this example.

Answer 1

A really simple way to do this would be to have a String ArrayList running alongside (for example, one called licenses) and use an if statement with indexOf to return if that license value is already in the List. Since the licenses ArrayList only has one value it can be easily searched with indexOf.

An example would be

private boolean checkLicense (String licenseNumber) {
        int i = licenses.indexOf(licenseNumber);
        if(i == -1) {
            return false;
        } else {
            return true;
        }
}

Similar code works in one of my projects where a dynamic List of motors for a robot checks to see if there's already a motor with the listed port before adding a new one.

Another method could use a for loop for a linear search such as

private boolean checkLicense (String licenseNumber) {
   for(int i = 0; i < (realtorList.size() - 1); i++) {
      if (licenseNumber.equals(realtorList[i].getLicenseNumber())) {
         return true;
      }
   }
   return false;
}

This would perform a linear search of each and every object until it finds it (it would need to be in a method like the one for the example above to work this way)