How to data add in List<Object> items in android

android, java

Solution

problem is here:

for (int i = 0; i < 5; i++) {
        item.setFirstName("AA::" + i);  <-- error happened here because item is null
        item.setLastName("BB::" + i);
        item.setAddress("New City " + i);
        item.setSex("Male");
        itemList.add(item); 
        item = new PersonalInfo();
    }

you need first initialize `item` then set data to that, so your code must be:

for (int i = 0; i < 5; i++) {
            item = new PersonalInfo();  <-- I've moved this line
            item.setFirstName("AA::" + i);
            item.setLastName("BB::" + i);
            item.setAddress("New City " + i);
            item.setSex("Male");
            itemList.add(item);

        }

Problem

I am a new android developer.I am developing a sample application .I want to add some data in a object list. My MainActivity.java class code: ``` public class MainActivity extends Activity { private PersonalInfo item; private List<PersonalInfo> itemList = new ArrayList<PersonalInfo>(); @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); for (int i = 0; i < 5; i++) { item.setFirstName("AA::" + i); item.setLastName("BB::" + i); item.setAddress("New City " + i); item.setSex("Male"); itemList.add(item); item = new PersonalInfo(); } for(PersonalInfo p:itemList){ System.out.println("First Name::"+p.getFirstName()); System.out.println("Last Name::"+p.getLastName()); } } } ``` My PersonalInfo.java class code: ``` public class PersonalInfo { private String firstName; private String lastName; private String address; private String sex; public String getFirstName() { return firstName; } public void setFirstName(String firstName) { this.firstName = firstName; } public String getLastName() { return lastName; } public void setLastName(String lastName) { this.lastName = lastName; } public String getAddress() { return address; } public void setAddress(String address) { this.address = address; } public String getSex() { return sex; } public void setSex(String sex) { this.sex = sex; } } ``` When I run it ,then show flowing error Thanks for your help.

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