String attribute of object always null in java

Question

I have an arraylist of string arrays I pull from a csv file and I use that array to initialize the person object. All of the variables have values but the string email is always null. I checked and it is at the fifth index of every string array and it is not null in the initial "people" arraylist of string arrays.

public class person {

int year;
int sex;
int college;
int housing;
String email;
double resp_probability;

public person(ArrayList<String[]> people, int a) {
    int year = Integer.parseInt(people.get(a)[0]);
    int sex = Integer.parseInt(people.get(a)[1]);
    int college = Integer.parseInt(people.get(a)[2]);
    int housing = Integer.parseInt(people.get(a)[3]);
    String email = people.get(a)[5]; //where I set a value for email.
}

public String getEmail() {
    return email;
}
}

Answer 1

Because you defining a new local string variable in the constructor. Instead you should use this.email then assign the value.

this.email = people.get(a)[5];

Similarly for the all other class member variables. null is the default value for any reference class member variable and zero for numerical variables like int.