Code Comments

Let’s say you have an ArrayList in Java.

ArrayList<String> a = new ArrayList<String>();
a.add("abc");
a.add("def");
a.add("ghi");

Now let’s say you wanted to grab the “def” object out of it. You could do this in the following way:

String b = a.get(a.indexOf("def"));

You can only retrieve an object from an ArrayList by its index. So a simple workaround is first to find the index of the object and then grab the object using that index.

This is a very trivial example, but this type of thing can be handy at times.

Note: If you are using a class like String from the Java framework that has an explicit equals method built into it, this will be easy. However, if the ArrayList contains objects of a custom class, you will likely need to override the equals and hashCode methods.