ARRAYS - Java Programming: From Problem Analysis to Program Design - page 567

boolean areEqualArrays( int [] firstArray, int [] secondArray)
{

if (firstArray.length != secondArray.length)
return false ;

for ( int index = 0; index < firstArray.length; index++)
if (firstArray[index] != secondArray[index]) //the
//corresponding elements
//are different

return false ;

return true ;

}

Now consider the following statement:

if (areEqualArrays(listA, listB))
...

The expression areEqualArrays(listA, listB) evaluates to true if the arrays listA
and listB contain the same elements; false otherwise.

Arrays as Parameters to Methods
Just like other objects, arrays can be passed as parameters to methods. The following
method takes as an argument any int array and outputs the data stored in each element:
public static void printArray( int [] list)
{

9

for ( int index = 0; index < list.length; index++)
System.out.print(list[index] + " ");

}

Methods such as the preceding one process the data of an entire array. Sometimes the
number of elements in the array might be less than the length of the array. For example,
the number of elements in an array storing student data might increase or decrease as
students drop or add courses. In situations like this, we only want to process the elements
of the array that hold actual data. To write methods to process such arrays, in addition to
declaring an array as a formal parameter, we declare another formal parameter specifying
the number of valid elements in the array, as in the following method:
public static void printArray( int [] list, int numOfElements)
{

for ( int index = 0; index < numOfElements; index++)
System.out.print(list[index] + " ");

}

The first parameter of the method printArray is an int array of any size. When the
method printArray is called, the number of valid elements in the actual array is passed
as the second parameter of the method printArray .