How to declare unique ArrayList ?
Answers were Sorted based on User's Feedback
Answer / kiran
you have SET INTERFACE in COLLECTION in java . where u can
store unique elements and if u try to add duplicate elements
it will raise an error
| Is This Answer Correct ? | 10 Yes | 3 No |
Answer / indresh_ips
Hey, Here is the program of Unique ArrayList.........
Just Run It........
import java.util.*;
class ArrayListUnique {
static public ArrayList uniqueArrayList(ArrayList arrl) {
int i;
for(int k=0;k<arrl.size();k++) {
Object s=arrl.get(k);
i=Collections.frequency(arrl,s);
for(int j=1;j<i;j++) {
arrl.remove(s);
}
}
return arrl;
}
public static void main (String[] args) {
ArrayList al= new ArrayList();
al.add("A");
al.add("A");
al.add("B");
al.add("C");
al.add("B");
al.add("A");
al.add("D");
al.add("D");
al.add("D");
al.add("D");
al.add("A");
al.add("B");
al.add("F");
al.add("G");
al.add("G");
al.add(10);
al.add(5);
al.add(10);
al.add(5);
System.out.println ("Before declaring unique:"+al);
ArrayList a=ArrayListUnique.uniqueArrayList(al);
System.out.println ("after declaring unique: "+a);
}
}
| Is This Answer Correct ? | 7 Yes | 2 No |
Answer / sudhakar
I have modified the above program. And made esay the
process.
import java.util.ArrayList;
public class UniqueArrayListValues {
static ArrayList assignValues() {
ArrayList a1 = new ArrayList();
a1.add("A");
a1.add("B");
a1.add("C");
a1.add("27");
a1.add("A");
a1.add("B");
a1.add("C");
a1.add("27");
a1.add("A");
a1.add("B");
a1.add("C");
a1.add("27");
return a1;
}
static ArrayList applyUniqueKey(ArrayList a1) {
ArrayList a2 = new ArrayList();
for (int i = 0; i < a1.size(); i++) {
if (!a2.contains(a1.get(i))) {
a2.add(a1.get(i));
}
}
return a2;
}
public static void main(String args[]) {
ArrayList beforeUniqueKey = assignValues();
System.out.println("Before applying Unique
Key:" + beforeUniqueKey);
ArrayList afterUniqueKey = applyUniqueKey
(beforeUniqueKey);
System.out.println("Afrer applying Unique
Key:" + afterUniqueKey);
}
}
| Is This Answer Correct ? | 5 Yes | 2 No |
Answer / surya chandra mohan , visakhap
small modification for first program. But that one is really excellent.i really proud Indresh_ips.
import java.util.*;
class ArrayListUnique2 {
static public ArrayList uniqueArrayList(ArrayList arrl) {
int i;
String check="";
for(int k=0;k<arrl.size();k++) {
String s=arrl.get(k).toString();
if(!check.contains(s)){
check = check+s+", ";
}else{
arrl.remove(s);
}
}
return arrl;
}
public static void main (String[] args) {
ArrayList al= new ArrayList();
al.add("A");
al.add("A");
al.add("B");
al.add("C");
al.add("B");
al.add("A");
al.add("D");
al.add("D");
al.add("D");
al.add("D");
al.add("A");
al.add("B");
al.add("F");
al.add("G");
al.add("G");
al.add(10);
al.add(5);
al.add(10);
al.add(5);
System.out.println ("Before declaring unique:"+al);
ArrayList a=ArrayListUnique.uniqueArrayList(al);
System.out.println ("after declaring unique: "+a);
}
}
| Is This Answer Correct ? | 1 Yes | 0 No |
Answer / ballu
i think java does not this in built facility ... you would
need to make sure that objects inserted in array are unique
( by overriding equals() and hash() method of Object class
| Is This Answer Correct ? | 3 Yes | 6 No |
Why javac is not recognized?
What is the use of bin and lib in JDK?
What are exception handling keywords in java?
Explain about field hiding in java?
What is stored procedure. How do you create stored procedure ?
How to access a method that it declared as protected?
where u use Abstraction and Interface in real time
Outline the major features of java.
What are voids?
Is simpledateformat safe to use in the multithreaded program?
What are the data types supported by java? What is autoboxing and unboxing?
What modifiers are allowed for methods in an interface?