Main.java Source code

Introduction

Here is the source code for Main.java

Source

//package com.java2s;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;

public class Main {
    @SuppressWarnings({ "unchecked", "rawtypes" })
    public static void UpperCaseItems(Collection collection) {

        //Basic iterator ... cannot modify collection using this method.
        Iterator iterator = collection.iterator();
        while (iterator.hasNext()) {
            Object object = iterator.next();
            if (object instanceof String) {
                System.out.println(((String) object).toUpperCase());
                //object = ((String) object).toUpperCase();  doesn't actually change the underlying object.
            }
        }

        //old school for loop ... can modify collection. This is not a structural change to the collection, just a change to the members. Structural collection changes in a loop is not recommended.
        if (collection instanceof ArrayList) {
            for (int i = 0; i < collection.size(); i++) {
                Object object = ((ArrayList) collection).get(i);
                String item = ((String) object);
                ((ArrayList) collection).set(i, item.toUpperCase());
            }
        }
    }
}