What is the difference between class array, object array and array class ?

If you are talking about java.util.Arrays class then see below

This class contains various methods for manipulating arrays (such as sorting and searching). This class also contains a static factory that allows arrays to be viewed as lists.

methods :

1. static boolean equals(Object[] a, Object[] a2)

2. static void fill(Object[] a, Object val)

3. static int binarySearch(Object[] a, Object key, Comparator c)

4. static boolean equals(Object[] a, Object[] a2)

5. static void sort(Object[] a)

and there overloaded forms(for each primitive data type) , uses of methods are clear from method names.

EXA

public static void main(String args[])
{
String[] strArr1 = {"Name","Sarje","Barange"};
String[] strArr2 = {"Name","Sarje","Barange"};
if(java.util.Arrays.equals(strArr1, strArr2))
{
System.out.println("Both are equal");
}
java.util.Arrays.sort(strArr1);
for(String str : strArr1)
{
System.out.println(str);
}
}

object array means what i think array of Objects if not then waiting for correct reply

thanks