array size

Is there a method that returns the number of elements in an array?

array.length ?

String[] strings = new String[10];
System.out.println(strings.length); // prints 10
Note that length is a property and not a method.

Since Arrays are always fixed size, why would one want to use length on array when the size is always already known ??
For ArrayList and others it may be reqd ....

Consider this:

public void printArray(int [] a)
{
for(int i=0;i<a.length;i++)
{
System.out.println(a[i]);
}
}

The method does not know the length of the array so it uses the field "length" to know the number of elements.

Also if you change the size of the array then you need to change everywhere you reference it by the hardcoded size.