Why 'if' statement is giving false result on comparing two indexes of arraylist even they have same value

Question

Today I found strange thing about ArrayList. For the following program:

    ArrayList<Integer> al = new ArrayList<Integer>();
    al.add(128);
    al.add(128);
    int t1 = al.get(0);
    int t2 = al.get(1);
    if(al.get(0)== al.get(1))
      System.out.print("true");
    else
      System.out.print("false");
    if(t1== t2)
      System.out.print("true");
    else
      System.out.print("false");

It it is giving result as falsetrue. For value less than 128, it is giving truetrue. I don't understand what is the logic behind it?

Try reading the answers to http://stackoverflow.com/q/20877086 if you want to understand why 128 is different from the lesser numbers. — Dawood ibn Kareem, Jun 19 '15 at 05:41

score 1 · Accepted Answer · answered Jun 19 '15 at 05:38

1

The Java Language Specification says that the wrapper objects for at least -128 to 127 are cached and reused.

answered Jun 19 '15 at 05:38

Hiren

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Why 'if' statement is giving false result on comparing two indexes of arraylist even they have same value

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