How to compare two Integers in java

Question

I want to compare elements in two list using < > ==

Is it the right way to use intValue()?

List<Integer> a = new ArrayList<Integer>();
a.add(129);

List<Integer> b = new ArrayList<Integer>();
b.add(128);

if(a.get(0).intValue() > b.get(o).intValue()) {
   // something
}

Answer 1

You're making it the right way.

As stated in the comments, you could also you compareTo(). An alternative to compareTo() is equals() which won't throw a NullPointerException in the case where the object is null.

Answer 2

Your way is correct. But with a small correction.

1)

a.get(0).intValue() == b.get(0).intValue()

2)

a.get(0).equals(b.get(0))

This is the problem in your code, you have to get(0), instead of get(1). Remember, in java it always start with 0.

Values can be compared using equals() or CompareTo method as well.

import java.util.ArrayList;
import java.util.List;

public class TestClass {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        List<Integer> a= new ArrayList<Integer>();
        a.add(128);

        List<Integer> b = new ArrayList<Integer>();
        b.add(128);

        if(a.get(0).intValue() == b.get(0).intValue()){
            System.out.println("success");
        }else{
            System.out.println("failure");
        }
        if(a.get(0).equals(b.get(0))){
            System.out.println("success");
        }else{
            System.out.println("failure");
        }

    }

}