CODEWITHSUNDEEP
javaarraylist
Jinx3y
Jinx3y

Reputation: 53

Searching through an ArrayList

I have an array list comprised of Objects. Each object is comprised of Strings.

object first = (String a,String b,String c)
object second = (String d,String e,String f,String g)
object third =  (first,second,String h,String i)

the "third" object is what is pumped into the ArrayList.

How do I search through this ArrayList for a specific string and then return the index of the containing element of the ArrayList (for deletion, display, etc)?

Upvotes: 0

Views: 3693

Answers (3)

Jinx3y
Jinx3y

Reputation: 53

Here is an example

    import java.io.FileNotFoundException;

public class AddressBook {

    public static void main(String[] args) throws FileNotFoundException {
//        new AddressBookGUI();
        ContactBook c = new ContactBook();
        c.readFromFile("input.txt");
        System.out.println(c.getContact(0));
        System.out.println(c.getContact(1));
        System.out.println(c.getContact(2));
        System.out.println(c.getContact(3));
        System.out.println(c.getContact(4));
        System.out.println(c.contactList.indexOf("Last"));
    }
}

Here is the output:

run:
Last:First:MI:Street:City:State:ZipCode:HomePhone:CellPhone
Anderson:Robert:M.:19 AnyStreet:AnyCity:AnyTown:12345:(123)456-7890:(987)654-3210
MacLean:Jerry:A.:34th Ave West, #12:Brooklyn:NY:66978:(447)582-9943:(447)221-7735
LastName:First:MI:Street:City:State:ZipCode:HomePhone:CellPhone
Macintosh:Jerry:A.:34th Ave West, #12:Brooklyn:NY:66978:(447)582-9943:(447)221-7735
-1
BUILD SUCCESSFUL (total time: 0 seconds)

Key point is that every indexOf() returns -1 instead of the index.

Upvotes: 0

Steven Feldman
Steven Feldman

Reputation: 841

What are these objects exactly? Are they Classes that you defined? If so, you need to go through your Object Array, and have each oject have a .contains() method, which should have the code ArrayList.indexOf(myString)

for(int i=0; i<array.size(); i++)
{
    Object o=array.get(i);
        if(o.contains("STRING"){
            //do code
    }
}


class Object{
  public boolean contains(String s){
    return (array.contains(s));
  }

}

Upvotes: 1

Travis Webb
Travis Webb

Reputation: 15028

ArrayList.indexOf(myString)

http://download.oracle.com/javase/6/docs/api/java/util/ArrayList.html#indexOf(java.lang.Object)

Upvotes: 0

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